Can Astigmatism Get Worse? Causes and Warning Signs

Yes. Astigmatism can increase or decrease over time. In adults, a frequent reason is a change in the curve of the lens inside the eye, which can come before a cataract. A steady rise in your teens or twenties needs a closer look: early keratoconus, a thinning of the cornea into a cone shape, causes astigmatism and may keep progressing for 10 to 20 years. When astigmatism changes, your glasses or contact lens prescription is updated to match, since those are its most common treatments. If yours changes at every visit, ask for a corneal map too. Our astigmatism guide covers the basics.

Key takeaways

Astigmatism can go up or down over time, and in adults a frequent reason is a change in the curve of the lens inside the eye.
A steady rise in astigmatism during your late teens or twenties can signal keratoconus, a thinning of the cornea into a cone, so ask for a corneal map.
Later in life, a glasses prescription that has to change often can be a symptom of a cataract, a cloudy area in the eye's lens.
A yearly eye exam is recommended for most adults, and children should have one every year because their vision may change often during the school years.

Does astigmatism get worse with age?

It can, in either direction. In adults, the lens inside the eye is often the reason: its curve can change and raise or lower astigmatism, a shift that frequently happens in adulthood and can come before a cataract develops.

Astigmatism itself often begins early. Some people are born with it, many develop it as children or young adults, and some develop it after an eye injury or eye surgery.

Later in life, mention it at your exam if your prescription keeps changing. Having to change the prescription for your glasses or contact lenses often is one of the symptoms of a cataract, a cloudy area in the lens of the eye. Our guide to cataracts explains how we track one until it's time for surgery.

At every comprehensive eye exam we refine the astigmatism axis along with your distance and near prescription, so a shift shows up from one year to the next.

What can make astigmatism worse?

Astigmatism happens when the cornea (the clear front layer of the eye) or the lens inside the eye has a different shape than normal, so anything that changes either shape can change it. Causes of change include:

Changes in the curve of the eye's lens, which frequently happen in adulthood and can raise or lower astigmatism
A cataract, which can make your prescription change often
Keratoconus, in which the normally round cornea becomes thin and cone shaped
An eye injury or eye surgery; deeper scratches and other injuries can scar the cornea and cause vision problems

The timing is a clue. Lens changes frequently happen in adulthood, and cataracts mostly later in life, since most cataracts are related to age. A change after an injury or surgery has a clear starting point. Astigmatism that climbs through the late teens and twenties can be an early sign of keratoconus, so it calls for a corneal map.

When is worsening astigmatism a sign of keratoconus?

When it keeps climbing in a teenager or young adult. Keratoconus is a condition in which the normally round cornea becomes thin and irregular, or cone shaped. In the early stages it causes mild nearsightedness and astigmatism that glasses or soft contact lenses can correct, so at first it can look like an ordinary prescription change.

Symptoms usually appear in the late teens or early 20s, and keratoconus may progress for 10 to 20 years before it slows. As the cornea changes, it can lead to blurred vision that standard corrective lenses can't improve, called irregular astigmatism.

Tell us at your exam if any of these apply:

Your astigmatism has gone up at each of your last few visits.
One eye is noticeably worse than the other.
New glasses never feel as crisp as they should.
Glare and bright light bother you more than they used to, which can be an early keratoconus symptom.

Those patterns call for corneal imaging along with an updated prescription. For keratoconus, the AOA advises regular corneal curvature measurements and tests for irregular astigmatism. Corneal cross-linking halts or slows progression; the AOA says it is indicated early after diagnosis, or later if the glasses prescription is still increasing. At our keratoconus center we map the cornea with topography and tomography, and documented progression starts the cross-linking conversation. We co-manage cross-linking with corneal surgeons.

Is astigmatism genetic?

Often, yes. The AOA describes astigmatism as hereditary and usually present from birth, though the National Eye Institute notes that many people develop it as children or young adults. Refractive errors in general run in families: you're at higher risk if family members wear glasses or contact lenses.

Heredity isn't the whole answer. Doctors don't know what causes astigmatism, there's no way to prevent it, and some people develop it after an eye injury or surgery.

Keratoconus runs in families too: one in 10 people with keratoconus has a close family relative with the disorder. If a parent or sibling has it, mention that when you book, and we'll start with a baseline corneal map.

Check children even if they don't complain. Mild astigmatism may cause no symptoms, and children may be less likely to realize their vision isn't normal. Our pediatric eye exams measure how clearly each eye sees.

Why is driving at night with astigmatism so hard?

Trouble seeing at night is one of the most common symptoms of astigmatism, and refractive errors can make you see glare or a halo around bright lights. On the road, headlights and streetlights can look blurred or haloed.

Even astigmatism you hardly notice in daylight can do this, since a small amount that daytime hides can smear points of light at night.

What helps:

Wear your full, current prescription when you drive, astigmatism correction included.
Ask about an anti-reflective coating, which cuts reflections off the lens surfaces. For night drivers we pair precise correction with a quality anti-reflective coating.
Tinted "night driving" lenses are rarely the answer: any tint cuts the light you have to see by at night.
If you're having trouble seeing at night or recovering from the glare of oncoming headlights, slow down and avoid driving at night until your eyes are checked.

Glare at night can also come from dry eye or an early cataract. Our night vision guide explains how one exam tells the causes apart.

How we track changing astigmatism at Cohenmehr Optometry

Our Los Angeles eye doctors compare each visit with the one before. Corneal topography, a color map of the cornea's curve, is done in our office, and the images become your baseline: next year's exam is compared against them, so change is caught while it's still subtle.

If the map points to keratoconus, Dr. Brandon Cohenmehr oversees your care here. He monitors the cornea for progression and coordinates corneal cross-linking with corneal surgeons, and when glasses stop helping he fits scleral lenses or other specialty lenses.

Bring your current glasses and any old prescriptions to the visit, and if your astigmatism has been changing, say so when you book.

Questions patients ask

Can astigmatism cause headaches?

Yes. Headaches and eye strain are among the most common symptoms of astigmatism, along with blurry vision, squinting to see clearly and trouble seeing at night. If you've been squinting at night, re-reading lines or getting headaches by afternoon, the refraction at a comprehensive eye exam usually shows why. Glasses or contact lenses, the most common treatments, correct the astigmatism behind it.

Can astigmatism cause a lazy eye?

It can in children. Refractive errors, astigmatism among them, are one cause of amblyopia (lazy eye): if they aren't treated, the brain may start to rely more on the eye with stronger vision. Parents often don't know until an eye exam finds it, and the sooner treatment starts, the better. Our amblyopia guide explains the treatment.

How often should you get your eyes checked for astigmatism?

We recommend a yearly exam for most adults; healthy adults in their 20s and 30s whose prescription hasn't changed can sometimes stretch to every two years. Children should have an eye exam every year, because vision may change often during the school years. Keratoconus is different: the AOA advises regular corneal curvature measurements and tests for irregular astigmatism, and we see younger patients with fast-changing corneal maps more often.

Can rubbing your eyes cause astigmatism?

Hard, frequent rubbing can contribute to keratoconus, which causes astigmatism that may keep increasing. The AOA lists frequent eye rubbing, especially aggressive "knuckling" rubbing, as a keratoconus risk factor. Excessive rubbing and a tendency toward allergies are both environmental factors that may contribute to it. If itchy eyes keep you rubbing, treat the itch; our page on eye rubbing and keratoconus explains how.

Sources

Written by

Dr. Bijan Cohenmehr, OD

Founder of Cohenmehr Optometry, in practice for over 40 years. He leads the practice’s dry eye care and myopia management. A graduate of SUNY College of Optometry.

About Dr. Bijan →

Can Astigmatism Get Worse? What Changes It and When to Get Checked