What Causes Astigmatism to Worsen: Key Causes 2026

Astigmatism worsens when the shape of the cornea or crystalline lens changes in a way that increases the mismatch between the two principal meridional focal points, sending light to multiple locations on the retina rather than one. The most common reasons this happens include progressive corneal disease, physical trauma from habitual eye rubbing, post-surgical changes, aging of the lens, and systemic conditions including uncontrolled diabetes mellitus and pregnancy-related hormonal shifts.

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According to the National Eye Institute, astigmatism affects approximately one in three people in the United States, and while many cases remain stable throughout life, a clinically meaningful number progress over time because of identifiable, often preventable or treatable causes. Recognizing which cause applies to you is the difference between watching and waiting and getting the specialist evaluation that protects your long-term vision.

This article covers every major reason what causes astigmatism to worsen, from the biomechanical to the systemic to the behavioral, and tells you exactly when a prescription change stops being routine and starts being a warning sign.

What Causes Astigmatism to Worsen

Astigmatism worsens when an active, ongoing physical or biochemical process changes the curvature of the cornea or the optical geometry of the crystalline lens beyond what glasses or contact lenses corrected at your last prescription.

The causes fall into three broad categories. The first is structural corneal disease, where the tissue itself is losing tensile strength and deforming progressively. The second is external mechanical forces, including eye rubbing and poorly fitted contact lenses, that physically reshape the corneal surface over time. The third is systemic or hormonal changes that alter corneal hydration, refractive index, or the optical contribution of the lens.

Not every change in astigmatism means something is wrong. Prescription adjustments of 0.25 diopters at an annual exam can reflect normal measurement variability. What matters is the pattern: a change of 0.50 diopters or more in the cylindrical power at a single exam, a change in the axis of astigmatism, or a trend of worsening across two or more consecutive visits.

People with connective tissue disorders including Marfan syndrome or Ehlers-Danlos syndrome carry a higher baseline risk of progressive astigmatism because the structural collagen abnormalities affecting other organ systems also apply to corneal tissue.

How Astigmatism Affects Vision and Why It Changes

Astigmatism produces blurred, distorted, or doubled vision because the eye, instead of having one spherical focal point, has two separate focal lines oriented at different angles, a result of asymmetric curvature in the cornea or lens.

Think of normal vision like a perfectly spherical lens that focuses all incoming light to a single clean point on a screen behind it. Astigmatism is what happens when that lens is shaped more like the side of a football. Light rays entering through the steeper meridian focus short of the retina, while rays entering through the flatter meridian focus further back. The retinal image is never sharp because no single point brings all meridians into simultaneous focus.

When astigmatism worsens, the gap between these two focal lines widens. A small amount of astigmatism (under 1.00 diopter) may cause only mild blur that many people adapt to. Once astigmatism reaches 2.00 diopters or more, distortion becomes harder to ignore: straight lines appear tilted, headlights at night produce starburst patterns, and near and distance tasks both require more effort.

The specific symptom pattern depends on which type of astigmatism is increasing and why. Against-the-rule astigmatism (where the cornea curves more steeply in the horizontal meridian) is more common in older adults and in conditions affecting the inferior peripheral cornea. With-the-rule astigmatism (steeper vertical meridian) is more common in children and younger adults. A shift in the axis of astigmatism across annual exams, not just a change in magnitude, is a clinically meaningful sign that the corneal shape is actively changing rather than simply being remeasured slightly differently.

Corneal Astigmatism vs Lenticular Astigmatism Worsening

Astigmatism that worsens can originate from the cornea, the crystalline lens, or a combination of both, and distinguishing between these sources is essential for understanding why it is progressing.

Corneal astigmatism accounts for the majority of total astigmatism in most eyes and arises from asymmetric curvature of the anterior or posterior corneal surface. This is the type most likely to progress actively, particularly in conditions like keratoconus or after refractive surgery. The cornea contributes roughly 65 to 75 percent of the total refractive power of the eye, so even small curvature changes produce clinically noticeable prescription shifts.

Lenticular astigmatism originates from the crystalline lens. It can be present from birth due to lens tilt or asymmetric lens shape, or it can develop later as the internal structure of the lens changes with age. Nuclear cataract formation, the clouding of the central lens nucleus, progressively alters the refractive index distribution within the lens and can shift both the spherical and cylindrical components of the prescription. Some people notice their reading vision temporarily “improves” as a nuclear cataract develops (a phenomenon called second sight), only to find their overall astigmatism has worsened when fully assessed.

For people over 60, lenticular astigmatism becomes an increasingly prominent contributor to total astigmatism changes, while corneal changes tend to drive worsening in people under 40.

Key Takeaway: Astigmatism worsens through two distinct pathways, corneal curvature changes and lens geometry changes, and identifying which is active in your eye determines whether treatment is surgical, optical, or systemic.

Keratoconus: The Most Common Progressive Cause of Astigmatism

Keratoconus is a progressive corneal ectatic disease in which the central or paracentral cornea gradually thins and bulges forward, producing rapidly worsening irregular astigmatism that often cannot be fully corrected with standard glasses.

The underlying mechanism involves degradation of collagen crosslinks within the corneal stroma. Research published in Investigative Ophthalmology and Visual Science has identified elevated levels of matrix metalloproteinases (MMP-1, MMP-2, and MMP-9) in the corneal epithelium and stroma of keratoconus patients. These enzymes break down the covalent bonds that hold collagen fibrils together in the stroma, reducing the tensile strength of the corneal tissue. As strength decreases, normal intraocular pressure, typically 10 to 21 mmHg, is sufficient to push the weakened cornea forward in a progressive cone-like deformation.

The National Eye Institute estimates keratoconus affects approximately 1 in 2,000 people in the general population, though some population-based studies suggest higher prevalence closer to 1 in 375. It typically begins in the teens or early twenties and progresses most rapidly through the 20s, with many cases stabilizing naturally by the mid-30s to 40s.

Key risk factors for keratoconus-related astigmatism worsening include:

• A personal or family history of keratoconus (first-degree relatives have a 10 to 15 percent risk)
• Chronic eye rubbing (detailed in a separate section below)
• Atopic disease including allergic conjunctivitis, eczema, or asthma
• Down syndrome (trisomy 21 carries a markedly elevated keratoconus risk)
• Connective tissue disorders including Marfan syndrome and Ehlers-Danlos syndrome

Corneal collagen crosslinking (CXL), a procedure using riboflavin eye drops combined with ultraviolet-A light to create new covalent bonds in the stroma, is the only proven treatment for halting keratoconus progression. A landmark 2016 randomized controlled trial published in Ophthalmology confirmed that CXL halts corneal progression in 90 to 95 percent of treated eyes at 3-year follow-up. Early detection is essential because CXL cannot reverse existing ectasia; it can only prevent further worsening.

Corneal Ectasia After LASIK and Refractive Surgery

Post-LASIK ectasia is a complication of laser refractive surgery in which the remaining corneal tissue below the ablation zone lacks sufficient biomechanical strength to resist deformation by intraocular pressure, causing progressive irregular astigmatism months to years after surgery.

LASIK removes corneal stromal tissue through laser ablation to correct refractive error. When preoperative screening fails to detect a subclinical susceptibility (including undiagnosed early keratoconus, thin corneas, or steep curvature), or when the residual stromal bed after ablation is thinner than approximately 250 to 300 microns, the remaining tissue may progressively ectase. A 2022 review published in JAMA Ophthalmology identified that the incidence of post-LASIK ectasia ranges from approximately 0.02 to 0.6 percent of procedures, with the wide range reflecting differences in screening rigor across practices and time periods.

The astigmatism produced by post-LASIK ectasia is irregular, meaning it does not follow a simple two-meridian pattern that glasses can fully correct. Patients typically notice increasing blur, worsening halos and glare, and a prescription that keeps changing without stabilizing.

Photorefractive keratectomy (PRK) carries a lower ectasia risk than LASIK for borderline corneas because it does not create a flap, preserving anterior stromal integrity. Small incision lenticule extraction (SMILE) also preserves the anterior stroma more completely than LASIK, which may offer a lower ectasia risk profile in patients near the borderline, though direct comparative long-term data are still accumulating as of 2026.

For anyone who has had LASIK and notices increasing blur, increasing astigmatism prescription changes, or difficulty achieving clear vision with glasses, evaluation by a corneal and refractive subspecialist using Scheimpflug tomography (Pentacam or equivalent) is appropriate to rule out early ectatic progression.

Key Takeaway: Post-LASIK ectasia and keratoconus share the same underlying mechanism of corneal biomechanical instability, and both require specialist evaluation rather than simply stronger glasses to manage safely.

Does Eye Rubbing Cause Astigmatism to Get Worse

Habitual eye rubbing is a direct mechanical cause of progressive corneal astigmatism, and the evidence for this relationship has become substantially clearer over the past decade.

Biomechanical studies using finite element modeling, including research published in Investigative Ophthalmology and Visual Science, have quantified the intraocular pressure spikes generated by eye rubbing. A single forceful rub of the closed eyelid can transiently elevate intraocular pressure to 40 mmHg or higher, far above the normal range of 10 to 21 mmHg. Repeated exposure to these pressure spikes applies cyclical mechanical stress to corneal collagen fibrils. In a cornea with normal tensile strength, this stress is tolerable. In a cornea with reduced crosslink density (as in subclinical or early keratoconus), each rubbing episode compounds the biomechanical damage, stretching and thinning the tissue and advancing the ectatic process.

Eye rubbing is also the primary mechanism connecting atopic eye disease to keratoconus. People with atopic keratoconjunctivitis rub their eyes frequently to relieve intense itching. The inflammatory mediators released during allergic responses (including mast cell-derived proteases and prostaglandins) are themselves mildly damaging to corneal stromal collagen. Combined with the mechanical rubbing, the corneal degradation is compounded from two directions simultaneously.

To stop this from driving astigmatism worsening:

1. Identify the underlying reason for rubbing: allergic conjunctivitis, dry eye disease, or habit.
2. Treat the root cause with an optometrist or ophthalmologist using appropriate antihistamine eye drops or artificial tears.
3. Replace eye rubbing with gentle, closed-eye pressure applied with one finger to the brow bone rather than the globe.
4. If you have known keratoconus, treat eye rubbing cessation as a medical priority, not a preference.

Children and teenagers with atopic disease and a family history of keratoconus should be evaluated annually by an optometrist or ophthalmologist for early topographic signs of corneal ectasia.

Can Screen Time and Digital Device Use Worsen Astigmatism

Screen time does not directly cause astigmatism to worsen through the screen itself, but the visual behaviors associated with prolonged near work can contribute to prescription changes over time through related mechanisms.

The most relevant mechanism involves the relationship between sustained near work and myopia progression, which often co-occurs with astigmatism. Research from several large prospective studies in Asia and Europe, including a 2020 meta-analysis published in Ophthalmology, found that sustained near work without adequate outdoor light exposure is the primary environmental driver of childhood myopia progression. In eyes that are both myopic and astigmatic, myopia progression is frequently accompanied by measurable changes in astigmatic power and axis.

A separate but related issue is accommodation fatigue. The ciliary muscle (the ring-shaped muscle controlling lens curvature via the zonular fibers) sustains prolonged contraction during near work. Over months and years of intense near work, the accommodative system may not fully relax between sessions, contributing to apparent prescription shifts that can partially mimic astigmatism worsening on standard refraction testing.

Outdoor time appears to be the most protective factor. The National Eye Institute has highlighted research indicating that at least 90 minutes of outdoor light exposure per day in children and teenagers significantly reduces the rate of myopia progression, which secondarily reduces the rate of associated astigmatism change.

Screen time has not been shown in controlled human studies to directly deform the corneal shape. The concern is more accurately framed as: screen-related behavioral patterns (reduced outdoor time, sustained near work without breaks, reduced blink rate causing dry eye) create conditions that accelerate related refractive changes, including astigmatism, particularly in genetically susceptible individuals under 25.

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Contact Lens Warpage and Astigmatism Changes

Contact lens warpage refers to temporary or semi-permanent changes in corneal curvature caused by wearing contact lenses that apply uneven pressure or altered oxygen distribution to the corneal surface, producing measurable changes in astigmatism.

Rigid gas permeable (RGP) contact lenses are the most common cause of contact lens warpage. RGP lenses sit directly on the tear film and, over time, physically mold the anterior corneal surface. This can be intentional (as in orthokeratology, or Ortho-K, where overnight RGP wear deliberately reshapes the cornea to reduce myopia) or unintentional (when a poorly fitted RGP gradually flattens or steepens specific corneal meridians). In either case, the result is a corneal surface shape that no longer matches the person’s natural prescription, and a refraction performed while the warpage is present gives a misleadingly altered astigmatism reading.

Even soft toric contact lenses can cause minor but measureable warpage in sensitive corneas, particularly when overworn, fitted incorrectly, or used with extended wear schedules.

The practical implication is important: anyone being evaluated for new glasses, a pre-surgical examination for LASIK, or a possible keratoconus diagnosis must stop wearing contact lenses for a defined period before the examination.

Contact lens warpage-related astigmatism changes are generally reversible once lens wear stops and the cornea returns to its natural shape. If the astigmatism does not normalize after appropriate discontinuation, this is a signal that a structural corneal issue may be present and warrants corneal topography by an optometrist or ophthalmologist.

Key Takeaway: Contact lens warpage is reversible and often overlooked as a cause of apparent astigmatism worsening; a prescription change should always be assessed after an adequate lens-free washout period.

How Diabetes and Systemic Disease Affect Astigmatism

Uncontrolled diabetes mellitus can cause measurable and sometimes rapid astigmatism changes through its effect on the cornea, the crystalline lens, and the fine neural structures supplying the ocular surface.

The mechanism operates at two levels. First, elevated blood glucose alters the osmotic balance within the corneal stroma, causing fluid shifts that temporarily change corneal hydration and curvature. This is why some people with poorly controlled diabetes notice their vision and prescription fluctuating significantly from day to day or week to week. The National Institutes of Health has documented that glycemic fluctuation affects not only visual acuity but also the measured refraction, including the astigmatic component.

Second, long-standing diabetes causes diabetic corneal neuropathy, progressive loss of subbasal corneal nerve fiber density. The corneal nerves are not just sensory; they release neuropeptides including substance P and insulin-like growth factor, which maintain corneal epithelial health and stromal structure. When nerve density drops, the corneal surface becomes irregular, contributing to measurable changes in astigmatism that are not caused by curvature change per se but by epithelial surface irregularity detectable on corneal topography.

Other systemic diseases that can contribute to astigmatism worsening include:

• Thyroid eye disease (Graves orbitopathy): orbital inflammation changes the position and tilt of the globe, altering the axis and magnitude of astigmatism
• Sjögren’s syndrome: severe dry eye from lacrimal gland destruction causes tear film irregularity that worsens functional astigmatism
• Sarcoidosis and other uveitic conditions: posterior segment inflammation or anterior chamber involvement can alter lens position and produce secondary astigmatism

People with any of these systemic conditions should have their eyes examined by an ophthalmologist at least annually, as astigmatism changes in this context can signal disease activity rather than simple refractive drift.

Astigmatism Getting Worse During Pregnancy and Hormonal Changes

Pregnancy is a recognized cause of temporary astigmatism worsening, and the mechanism is grounded in the well-documented effect of reproductive hormones on corneal tissue.

Research published in the British Journal of Ophthalmology has identified progesterone receptors in human corneal epithelial cells, confirming that the cornea is a direct target tissue for sex hormones. During pregnancy, rising levels of progesterone and estrogen alter corneal hydration by changing the fluid dynamics of the corneal stroma. A more hydrated cornea has a slightly altered curvature and changes in refractive index. This produces prescription shifts, including changes in astigmatic power and axis, that can be measurable from as early as the first trimester and typically peak in the third trimester when hormonal levels are highest.

The practical consequence is that eye care professionals and ophthalmologists’ clinical guidelines advise against getting a new glasses or contact lens prescription during pregnancy, particularly in the second or third trimester, because the measured prescription may not reflect the stable postpartum state.

Corneal changes during pregnancy are generally reversible, returning to baseline within one to three months postpartum as hormone levels normalize. However, pregnancy can unmask a latent susceptibility to keratoconus. In women with subclinical keratoconus who were previously undiagnosed, the hormonal-related reduction in corneal biomechanical resistance combined with the weight of the pregnancy on the overall body (and thus on the eye position during sleep in lateral decubitus position) can trigger a first episode of clinically apparent progression.

Women who are planning pregnancy and have any prior history of astigmatism changes, abnormal corneal topography findings, or a family history of keratoconus should have a baseline corneal tomogram performed before conception. If keratoconus is detected and active, corneal collagen crosslinking before pregnancy, where timing allows, is a reasonable preventive strategy discussed with a corneal subspecialist.

Can Astigmatism Worsen with Age in Adults

Astigmatism does change with age in most adults, and the direction and mechanism of that change shift at different stages of life.

In younger adults (20s to 40s), the most common progressive corneal change beyond structural disease is a gradual shift from with-the-rule astigmatism (steeper vertical corneal meridian) toward against-the-rule astigmatism (steeper horizontal meridian). Research published in Ophthalmology has documented this trend across large adult population samples, attributing it to age-related changes in the eyelid tension applied to the superior and inferior corneal surface. As the upper eyelid loses elasticity, the vertical molding pressure it applies to the cornea decreases, and the horizontal meridian becomes relatively steeper by comparison.

The crystalline lens becomes increasingly relevant after 50. Nuclear cataract formation changes the refractive index distribution within the lens nucleus, which can shift the cylindrical component of the total refraction by 1.00 diopter or more as the cataract matures. This is lenticular astigmatism worsening caused by internal lens change rather than by any corneal disease. In this scenario, the appropriate treatment is cataract surgery with a toric intraocular lens implant, not a corneal procedure.

Older adults taking chronic systemic medications should be aware that certain drugs affect the lens and intraocular pressure in ways that can secondarily alter astigmatism:

• Long-term oral corticosteroids (e.g., prednisone) increase the risk of posterior subcapsular cataract formation, which can alter the astigmatic refraction
• Some antipsychotic medications have been associated with anterior lens changes
• Topical ophthalmic medications that lower intraocular pressure (used for glaucoma) can slightly alter corneal biomechanics in susceptible individuals

Annual dilated eye examinations with a full manifest refraction are appropriate for adults over 50 who have any known astigmatism, both to track the corneal contribution and to monitor lens status.

Key Takeaway: Aging shifts astigmatism in a predictable direction from with-the-rule to against-the-rule and adds a progressive lenticular component from cataract formation, two distinct mechanisms requiring different clinical responses.

Astigmatism Worsening in Children and Adolescents

Astigmatism in children can worsen as part of normal visual development during the school-age years, but it can also signal early keratoconus, and distinguishing between the two has long-term consequences for the child’s visual future.

Normal childhood astigmatism changes: Most children are born with some corneal astigmatism. Studies published in Investigative Ophthalmology and Visual Science have tracked cohorts showing that astigmatism measured in infancy is often higher than in school-age children, reflecting a natural process of corneal regularization during the first two years of life. After age 5, astigmatism tends to stabilize. Incremental changes of 0.25 to 0.50 diopters at annual visits during the school years can reflect normal measurement variability or mild progression associated with myopia development.

Astigmatism worsening that should prompt specialist evaluation in children includes:

• Any change of 0.75 diopters or more in cylindrical power at a single annual exam
• A change in the axis of astigmatism, not just the magnitude
• Best corrected visual acuity that does not reach 20/20 with properly prescribed spectacles (possible early irregular astigmatism)
• Concurrent rapid myopia progression
• Complaints of ghosting, monocular diplopia, or marked light sensitivity around halos
• A family history of keratoconus in a parent or sibling

The American Academy of Ophthalmology recommends that children with a sibling or parent with keratoconus receive annual corneal topography screening beginning at age 8 to 10, as ectatic disease onset in the second decade is not uncommon in high-risk families.

Pediatricians should be aware that children rarely volunteer visual complaints. Worsening astigmatism in a child may present as difficulty reading from the board at school, unusual head tilting, squinting, or declining academic performance rather than a direct complaint of blur.

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Can Astigmatism Get Worse Without Glasses or Correction

Not wearing glasses or contact lenses does not directly cause the underlying corneal or lens geometry to worsen, but chronic uncorrected astigmatism creates conditions that can contribute to worsening in specific populations and contexts.

The cornea itself will not deform simply because light is not corrected by a lens in front of it. The shape of the corneal surface is determined by its internal biomechanical properties, intraocular pressure, and external mechanical forces, not by whether the blurred image is corrected before it reaches the retina. So the premise that “not wearing glasses makes astigmatism worse” is not mechanistically accurate for most adults.

However, uncorrected astigmatism does cause problems that can indirectly promote worsening in certain groups:

1. Habitual squinting from uncorrected astigmatism increases pressure on the cornea from the eyelid muscles. In people with borderline corneal biomechanics, this may contribute to surface irregularity over time.
2. In children under age 8, significant uncorrected astigmatism can prevent the visual system from developing normal visual acuity in the affected eye, a condition called amblyopia (lazy eye). Amblyopia is not astigmatism worsening per se, but uncorrected astigmatism during the critical period of visual development permanently impairs acuity in a way that is not recoverable with glasses alone after age 8 to 10.
3. People with symptomatic uncorrected astigmatism are more likely to rub their eyes frequently due to visual fatigue and eye strain, creating the mechanical risk pathway described in the eye rubbing section above.

The correct framing for patients is: not wearing correction does not physically worsen the astigmatism itself in adults, but in children during the visual development window, the consequences of leaving it uncorrected are serious and time-limited. Adults should wear their prescribed correction for visual comfort, driving safety, and reduced eye strain, not because skipping it will structurally harm their cornea.

How to Tell If Your Astigmatism Is Getting Worse

Recognizing progressive astigmatism requires tracking both subjective visual symptoms and objective clinical measurements, because the two do not always change at the same pace.

Subjective signs that astigmatism may be worsening:

• Glasses or contact lenses that corrected your vision well at your last prescription now feel slightly off, particularly for distance or reading
• Headlights at night show more pronounced starburst or comet-tail patterns than before
• You notice a faint second image or ghost image alongside the main image, particularly with one eye closed
• Straight lines (door frames, architectural edges, monitor text) appear slightly tilted or wavy
• Increasing eye strain or headaches after visual tasks that were previously comfortable
• Difficulty seeing clearly at an intermediate distance (around arm’s length) without prescription adjustment

To document progression systematically before your next eye appointment:

1. Note the date the visual changes first became noticeable and describe the specific task that revealed them (reading in low light, night driving, computer work).
2. Test each eye separately: cover one eye at a time and compare the clarity of a specific reference object (a door frame, a distant sign) between eyes.
3. Check whether the change is consistent throughout the day or worse at specific times (worse after prolonged near work suggests an accommodative component, worse consistently suggests a structural change).
4. Bring your current glasses prescription (written on paper from your last exam) to your next appointment. A prescription change of 0.50 diopters or more in the cylinder power since your last visit is clinically noteworthy.
5. Ask specifically for a printout of your corneal topography results from each consecutive visit. Visual comparison of color maps from year to year shows whether the corneal shape is stable or shifting.

People who wear toric contact lenses should note whether their lenses feel like they are rotating or fitting differently than before, as this can reflect a change in the axis of the underlying astigmatism.

When to See an Eye Doctor for Worsening Astigmatism

The right provider and the right timeline for evaluation depend on the speed and pattern of your astigmatism change, not just the magnitude.

See an optometrist or ophthalmologist promptly (within 2 to 4 weeks) if you notice:

• A clear worsening of vision with your current prescription that was not present three months ago
• A change in how your toric contact lenses fit or rotate
• Monocular diplopia (double or ghost image with one eye open and one eye closed)
• Halos or streaks around lights that are new or noticeably worse than before

See an optometrist or ophthalmologist at your next scheduled annual appointment for:

• Gradual, modest changes in visual clarity that are not interfering with daily activities
• A minor prescription change confirmed at a routine annual exam

Request a referral to a corneal and refractive subspecialist (a board-certified ophthalmologist with fellowship training in cornea) if:

• Your prescription has changed by 0.50 diopters or more in cylinder power at a single annual exam
• Your best corrected visual acuity with glasses cannot reach 20/20
• Your eye care provider has noted an irregular pattern on corneal topography or tomography
• You have had LASIK and are experiencing worsening prescription changes more than 1 year post-operatively
• You are under 35 with progressive astigmatism and a family history of keratoconus

According to the American Academy of Ophthalmology, annual comprehensive eye examinations are the foundation for detecting astigmatism progression before it produces irreversible structural changes in the cornea.

Key Takeaway: A single prescription change of 0.50 diopters or more in the cylindrical power at one exam is the threshold that shifts astigmatism management from routine monitoring to specialist evaluation.

Emergency Symptoms: When Worsening Astigmatism Signals a Serious Eye Condition

Certain symptoms associated with worsening astigmatism require immediate emergency evaluation. Do not wait to see if these resolve on their own.

Call 911 or go to the nearest emergency room immediately if you experience:

• Sudden, severe loss of vision in one or both eyes (could indicate retinal detachment, central retinal artery occlusion, or acute corneal decompensation)
• Sudden severe eye pain accompanied by nausea, vomiting, and halos around lights (classic triad of acute angle-closure glaucoma, a surgical emergency in which intraocular pressure can reach 40 to 70 mmHg and permanently damage the optic nerve within hours)
• Chemical splash to the eye from any household or occupational substance (requires immediate irrigation and emergency evaluation regardless of whether vision seems intact initially)
• Sudden onset of flashing lights, a new dark curtain or shadow in the visual field, or a sudden increase in floaters in one eye (classic presentation of retinal tear or retinal detachment, which requires surgical repair within hours to preserve central vision)
• Visible change in the shape of the eye surface (protrusion, asymmetry, or clouding visible to you or another person looking at your eye)
• Eye trauma: any blunt or penetrating injury to the eye or orbit

These presentations can indicate acute angle-closure glaucoma, retinal detachment, corneal perforation, or acute keratoconus hydrops (sudden fluid accumulation within a severely ectatic cornea), and they require emergency ophthalmological assessment, not an urgent care appointment or a phone call to your optometrist.

For non-emergency but time-sensitive symptoms, including new monocular ghost images, rapid prescription changes within a few weeks, or new halos without pain or nausea, contact an ophthalmologist within 24 to 48 hours for a same-week appointment.

Frequently Asked Questions About Astigmatism Worsening

What causes astigmatism to get worse suddenly?

Sudden astigmatism worsening most commonly signals active corneal ectasia such as keratoconus, an acute corneal hydrops episode, or a rapid post-surgical change after LASIK or cataract surgery.
It can also occur with acute angle-closure glaucoma, which causes rapid changes in corneal curvature from elevated intraocular pressure and constitutes a medical emergency.
Any sudden worsening of astigmatism, particularly over days to weeks rather than the typical months to years, warrants urgent evaluation by an ophthalmologist within 24 to 48 hours.

Can astigmatism worsen if I don’t wear my glasses?

Not wearing glasses does not directly cause the cornea or lens to change shape in adults, so the underlying structural astigmatism does not worsen from skipping correction.
In children under age 8, however, significant uncorrected astigmatism during the critical visual development period can cause amblyopia, a permanent reduction in best corrected visual acuity that is not reversed by glasses alone once the developmental window closes.
Adults should wear their correction for visual comfort, driving safety, and reduced eye strain, not because their cornea will physically worsen from going without it.

Why is my astigmatism getting worse every year?

Annual prescription changes suggest an active ongoing process, and the most important distinction is between gradual, predictable age-related change and progressive structural corneal disease like keratoconus.
A change of 0.25 diopters annually is close to measurement variability, but consistent changes of 0.50 diopters or more per year, or any change in axis, warrants corneal topography or tomography to rule out active ectasia.
A corneal and refractive subspecialist can review serial topography maps and corneal thickness measurements to determine whether the annual changes reflect stable drift or active progression requiring treatment.

Does eye rubbing really make astigmatism worse?

Yes. Habitual eye rubbing generates transient intraocular pressure spikes estimated at 40 mmHg or higher per forceful rub, applying cyclic mechanical stress to the corneal stroma.
In corneas with reduced collagen crosslink density, as found in keratoconus and in some genetically susceptible individuals without yet-diagnosable keratoconus, repeated rubbing episodes progressively advance ectatic deformation of the corneal surface.
Treating the underlying cause of rubbing (allergic conjunctivitis, dry eye disease) and ceasing the rubbing habit is a clinically important intervention for anyone at risk of progressive corneal astigmatism.

Can astigmatism get worse during pregnancy?

Yes. Pregnancy causes temporary astigmatism changes through progesterone- and estrogen-mediated alterations in corneal hydration and curvature, effects documented in research published in the British Journal of Ophthalmology.
These changes typically peak in the third trimester and resolve within one to three months postpartum as hormone levels normalize.
Eye care professionals generally advise against updating a glasses prescription during pregnancy because the measured values may not reflect the stable postpartum baseline.

At what age does astigmatism stop getting worse?

There is no single universal age, but keratoconus-related astigmatism progression most often stabilizes naturally by the mid-30s to early 40s in people who do not undergo corneal collagen crosslinking.
Age-related lenticular astigmatism from nuclear cataract formation is a separate process that typically begins in the 50s and progresses until cataract surgery is performed.
Regular annual eye examinations with corneal topography remain appropriate throughout adulthood for anyone with a history of progressive astigmatism, as there is no guaranteed biological endpoint for all causes of worsening.

Astigmatism that keeps worsening is not just an inconvenience requiring a stronger prescription every year. The causes covered here range from the reversible (contact lens warpage, pregnancy-related hormonal shifts) to the progressive and structurally significant (keratoconus, post-LASIK ectasia), and the distinction matters enormously for long-term visual outcomes.

The most protective action you can take is consistent annual monitoring with an optometrist or ophthalmologist who performs serial corneal topography, not just a standard refraction. Catching the difference between a stable, mild prescription shift and active ectatic progression early is what makes treatments like corneal collagen crosslinking effective.

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If your astigmatism has changed noticeably since your last exam, make the appointment. If the change has been rapid, request a referral to a corneal subspecialist and ask specifically about corneal tomography. The information you now have about what is causing your vision to change is the foundation for asking the right questions at that visit.