Astigmatism changes throughout life, sometimes dramatically. Babies are frequently born with it, and most see it vanish within a year. In adults, astigmatism tends to hold steady through the twenties, thirties, and forties before shifting again after age fifty, when the cornea gradually reshapes itself in ways that alter both the amount and the orientation of the distortion. Whether astigmatism “goes away” depends entirely on which stage of life you’re in and what’s driving the irregularity in the first place.
Why Most Babies Lose Their Astigmatism
Newborns commonly have measurable astigmatism. Their corneas and lens surfaces haven’t yet settled into their final shape, so the curvature is often uneven enough to blur vision at certain angles. A large Italian birth cohort study found that astigmatism resolved spontaneously in the first year of life in almost all cases, driven by a natural flattening of the corneal and lens surfaces as the eye grows and these surfaces become less variable in their curvature.1PubMed Central. Ocular Refraction at Birth and Its Development During the First Year of Life in a Large Cohort of Babies in a Single Center in Northern Italy In other words, infant astigmatism is typically a byproduct of an eye still under construction. As both the cornea and the front surface of the lens become rounder and more symmetrical, the distortion fades on its own.
Research on infant eye development confirms that corneal curvature in young eyes tends to be steeper in one direction (called “with-the-rule” astigmatism, meaning the steepest curve is roughly vertical). Over the first months and years, both the cornea and the anterior lens surface flatten out, which pushes astigmatism downward.2Optometry and Vision Science. Refractive Astigmatism and the Toricity of Ocular Components in Human Infants So if your child was told they had astigmatism at a very early checkup and it later disappeared, that’s a normal developmental trajectory, not a measurement error.
School-Age Children and the Slow Drift
Once children pass the toddler years, astigmatism behaves differently depending on how much is there to begin with. A hospital-based study tracking Chinese school-age children over time found that kids with low astigmatism (up to about 1.50 diopters) saw a small, slow increase of roughly 0.02 diopters per year, while those starting with high astigmatism (3.00 diopters or more) actually experienced a decrease of about 0.05 diopters per year.3PubMed Central. Long-term astigmatism progression and its interaction with spherical equivalent in Chinese school-age children: A hospital-based cohort study So there’s a kind of regression toward the middle: mild cases creep up slightly, and more pronounced cases tend to shrink.
That same study also found that myopia and astigmatism interacted with each other. Children who were more nearsighted at the start tended to develop more astigmatism over time, while those who began with higher astigmatism showed slower progression of their nearsightedness. The type of astigmatism matters too. In preschoolers, astigmatism is primarily corneal in origin, and the lens of the eye doesn’t compensate for high levels of corneal irregularity the way it does in milder cases.4Optometry and Vision Science. Corneal and Lenticular Components of Total Astigmatism in a Preschool Sample For parents, the practical takeaway is that mild childhood astigmatism usually stays mild and may not need treatment, but significant astigmatism in a young child warrants regular monitoring because it can affect visual development.
The Relative Calm of Young and Middle Adulthood
If you’ve had a stable glasses prescription through your twenties and thirties, that’s not unusual. Both corneal and refractive astigmatism tend to hold fairly steady between the ages of roughly 20 and 49. An Australian population study found that the average amount of refractive astigmatism stayed around -0.44 diopters until age 50, after which it began climbing.5PubMed. Distribution of astigmatism as a function of age in an Australian population A separate analysis found that all major measurements of corneal and total astigmatism were stable across the 20-to-49 age range, then shifted by about 1.0 diopter in an against-the-rule direction afterward.6PubMed. Age-related changes in with-the-rule and oblique corneal astigmatism
This doesn’t mean nothing at all changes during these decades. Small fluctuations are normal, and factors like prolonged screen use, contact lens wear, or dry eye can make measurements vary from visit to visit without reflecting a true shift in the cornea. But for most people, the twenties through the mid-forties are the period when your astigmatism prescription is least likely to surprise you.
The Shift That Comes With Aging
After 50, astigmatism starts changing again, and the change is consistent enough across populations that researchers have mapped it in detail. The overall amount of astigmatism increases, and the orientation flips. Younger eyes tend to have with-the-rule astigmatism, where the steepest corneal curve is vertical. Older eyes shift toward against-the-rule astigmatism, where the steepest curve is horizontal.7PubMed. Age-Related Changes in Astigmatism and Potential Causes A population study in Iceland found the prevalence of against-the-rule astigmatism increased by about 5% every five years in people over 50.8PubMed. “With the rule” astigmatism is not the rule in the elderly
The Australian data put the trajectory in concrete terms: refractive astigmatism grew by roughly 1.00 diopter between age 50 and 90, while corneal astigmatism on its own stayed more stable until around age 80.5PubMed. Distribution of astigmatism as a function of age in an Australian population That gap is important because it tells us the lens inside the eye is contributing to the change, not just the corneal surface. Both corneal and internal (lenticular) components shift toward against-the-rule orientation over the decades.9PubMed. The components of adult astigmatism and their age-related changes
What’s actually happening to the eye? The cornea gradually steepens and becomes more spherical overall as you age. Younger corneas are more oval in cross-section, and older corneas round out.10PubMed Central. Measurement of corneal curvature in young and older normal subjects Meanwhile, the lens inside the eye stiffens and shifts in how it bends light. Because the cornea and the internal lens usually oppose each other’s astigmatism to some degree, changes in either one can throw the balance off, which is why total astigmatism often increases even as the cornea itself becomes more symmetrical.
This matters practically because someone who had cataract surgery planned around their corneal measurements may end up with a different amount of refractive astigmatism than expected. If the natural lens was partially canceling out corneal astigmatism, removing it during cataract surgery can unmask the full corneal irregularity.11PubMed. Axis difference between corneal and internal astigmatism to consider for toric intraocular lenses Toric intraocular lenses, designed to correct astigmatism at the time of cataract surgery, have been shown in a systematic review to produce better uncorrected distance vision and lower residual astigmatism compared with non-toric lenses combined with relaxing incisions.12PubMed. Toric Intraocular Lenses in the Correction of Astigmatism During Cataract Surgery: A Systematic Review and Meta-analysis
Eyelid Pressure, Lumps, and Other Mechanical Causes
Your eyelids exert constant gentle pressure on your cornea, and anything that changes that pressure can alter astigmatism. A chalazion, the firm bump that forms when an oil gland in the eyelid gets blocked, can press on the cornea and induce or worsen astigmatism, especially when the lump is large and sits on the upper lid.13PubMed Central. Multivariate analysis of the effect of Chalazia on astigmatism in children The cornea’s ability to resist deformation has measurable limits, and when a chalazion’s compressive force exceeds them, the cornea distorts.14PubMed Central. Effects of chalazia on corneal astigmatism Once the chalazion is treated or resolves on its own, the cornea typically rebounds and astigmatism decreases or returns to its previous state. So this is a clear case where astigmatism can appear and then genuinely go away.
Ptosis, where one eyelid droops lower than normal, creates a similar dynamic over a longer timeline. A drooping lid constantly presses on the cornea, changing its contour. A prospective study found that after surgical correction of congenital ptosis, the cornea flattened and returned closer to its normal anatomy as the chronic pressure was relieved.15PubMed Central. Effect of congenital ptosis correction on corneal topography- A prospective study The lesson here is that astigmatism driven by external mechanical force is often reversible once the force is removed.
A pterygium, the wedge-shaped growth of tissue that can encroach onto the cornea from the white of the eye, works differently. It distorts the cornea through a combination of traction, scarring, and altered tear pooling. The longer and larger the growth, the more astigmatism it induces.16Scientific Reports. Effect of pterygium on corneal astigmatism, irregularity and higher-order aberrations: a comparative study with normal fellow eyes Surgical removal usually reduces the astigmatism, though some residual corneal scarring can keep it from fully normalizing.
Keratoconus and the Kind of Change You Want to Catch Early
Not all astigmatism change is benign. Keratoconus is a condition where the cornea progressively thins and bulges into a cone shape, producing irregular astigmatism that worsens over time. It typically starts in the teenage years or early twenties and can progress for a decade or more. If your astigmatism is climbing steadily and your glasses prescription seems to stop working well between visits, keratoconus is one of the things your eye doctor should rule out.
Eye rubbing has been repeatedly linked to keratoconus development and progression. A review of the evidence concluded that rubbing causes thinning of the corneal cells, and the degree of damage depends on how hard and how often someone rubs.17PubMed Central. The correlation between keratoconus and eye rubbing: a review Vigorous or habitual rubbing can increase the likelihood of developing keratoconus, and any ongoing rubbing or contact lens trauma may contribute to its progression.18Eye & Contact Lens. Abnormal Rubbing and Keratectasia People with allergies are at particular risk because the itchiness driven by allergic eye disease leads to more rubbing, creating a vicious cycle.19PubMed Central. Relevance of IgE, allergy and eye rubbing in the pathogenesis and management of Keratoconus
Unlike the age-related astigmatism changes described above, keratoconus-driven astigmatism does not go away on its own. It requires treatment, ranging from specialty contact lenses to corneal cross-linking (a procedure that stiffens the cornea to halt progression) to corneal transplant in severe cases. Early detection through corneal topography mapping makes a major difference in outcomes.
When Dry Eye Makes Astigmatism Seem to Fluctuate
If your astigmatism measurements seem inconsistent from one visit to the next, dry eye could be part of the explanation. The instruments that measure corneal curvature rely on light reflecting off the tear film, and when that film is unstable or patchy, the readings become unreliable. A study on dry eye patients found that before treatment, the differences in astigmatism power and axis between two repeated measurements taken on the same visit were strongly correlated with how disrupted the ocular surface was.20PubMed Central. Effects of Rebamipide on Differences in Power and Axis of Corneal Astigmatism Between Two Intra-patient Keratometric Measurements in Dry Eyes After dry eye treatment improved the surface condition, the measurements became more consistent.
This doesn’t mean dry eye causes true astigmatism, but it can create the appearance of astigmatism changes that aren’t really structural. If you’re being evaluated for refractive surgery or a toric lens implant, getting dry eye under control first leads to more accurate planning. And if your prescription seems to bounce around without a clear trend, ask your eye care provider whether dry eye might be muddying the picture.
Pregnancy and Hormonal Changes
Pregnancy causes temporary shifts in many parts of the body, and the eyes are no exception. Fluid retention can change corneal thickness, the depth of the front chamber of the eye, and the overall length of the eyeball. A prospective study tracking women through pregnancy and the postpartum period found significant changes in corneal thickness and several other measurements of the front of the eye as the pregnancy progressed and after delivery.21PubMed Central. Evaluation of anterior segment parameters between pregnancy trimesters and postpartum with pentacam scheimflug ımaging: a prospective study However, the study did not find a statistically significant change in astigmatism itself across pregnancy trimesters. So while pregnancy can make your vision feel different and alter some eye measurements, it doesn’t reliably cause or fix astigmatism. Eye doctors generally recommend waiting several months after delivery before updating a glasses or contact lens prescription, because the hormonal swings take time to fully settle.
Orthokeratology and the Illusion of a Cure
Orthokeratology, or ortho-k, uses specially designed rigid contact lenses worn overnight to temporarily flatten the cornea and reduce both myopia and astigmatism during waking hours. The effect is real: the lenses reshape the corneal surface, reducing its central curvature.22PubMed Central. Effects of orthokeratology on corneal reshaping and the delaying of axial eye growth in children But it’s temporary. Once lens wear stops, the cornea reverts. A study tracking patients after about a month of discontinuing ortho-k found that the flat corneal meridian bounced back and corneal astigmatism increased in both groups that had been wearing spherical and toric ortho-k lenses.23PubMed. Corneal astigmatism after temporary discontinuation from long-term spherical and toric orthokeratology
Interestingly, younger wearers and those who had been using ortho-k lenses for longer showed more pronounced corneal astigmatism changes after stopping, suggesting that longer-term wear may produce slightly more persistent molding of the cornea. Still, “more persistent” doesn’t mean permanent. Ortho-k is a maintenance treatment, not a fix. It’s popular among parents seeking myopia control for their children, but it doesn’t eliminate the underlying astigmatism.
Laser Surgery and Why Corrections Can Drift
LASIK, PRK, and SMILE can all correct astigmatism by reshaping the cornea with a laser. These procedures are effective at hitting the intended refractive target at the time of surgery. However, the cornea is a living tissue, and its cellular responses to being reshaped can cause some degree of regression over the months and years that follow.24Medical hypothesis, discovery & innovation ophthalmology journal. Mechanisms of Optical Regression Following Corneal Laser Refractive Surgery: Epithelial and Stromal Responses The surface layer of the cornea can thicken to partially undo the change, and the deeper stromal tissue remodels over time. This regression is generally small and doesn’t bring someone back to their original prescription, but it’s why some people find they need a touch-up procedure or start using reading glasses sooner than expected after laser surgery.
A separate concern is that a cornea weakened by refractive surgery may be more susceptible to mechanical deformation afterward. The same compressive forces from eyelid pressure or eye rubbing that a normal cornea would shrug off might have a measurable effect on a post-LASIK cornea.14PubMed Central. Effects of chalazia on corneal astigmatism This is one reason surgeons screen carefully for keratoconus risk before performing laser correction and why post-operative patients are told to avoid rubbing their eyes.
How Measurement Tools Can Mislead
It’s worth knowing that the instruments measuring your astigmatism have their own margin of error. A study evaluating repeatability of corneal astigmatism measurements found that even with modern topography equipment, the average measurement varied by about 0.4 diopters in both younger and older adults, and the axis measurement varied by about 5.4 to 5.5 degrees between repeated readings.25PubMed Central. Distribution and Repeatability of Corneal Astigmatism Measurements (Magnitude and Axis) Evaluated With Color Light Emitting Diode Reflection Topography That means a “change” of a quarter-diopter from one visit to the next might be instrument noise rather than an actual shift in your eye. Small fluctuations in your prescription are expected and don’t necessarily mean your astigmatism is progressing or resolving.
This becomes especially relevant when you’re comparing measurements taken years apart, at different clinics, or with different equipment. The direction of a trend over multiple visits is more trustworthy than any single reading. If you’re concerned about whether your astigmatism is genuinely changing, the most useful thing you can do is keep consistent records at the same practice, ideally using the same instrument, so genuine trends can be distinguished from measurement variability.