What is an unusual intolerance to light called?

An unusual intolerance to light is called photophobia. It is a symptom rather than a disease on its own, and it usually points to an underlying cause such as dry eye, migraine, eye strain, contact lens irritation, or inflammation in the eye.

Why are my eyes more sensitive to light than they used to be?

Common reasons for new or increasing light sensitivity include dry eye, longer screen time, contact lens overwear, migraine, certain medications, and developing cataracts. An eye exam can find the cause; our medical eye care team evaluates light sensitivity at all five clinics.

Can contact lenses make my eyes sensitive to light?

Yes. Lenses worn too long, lenses that fit poorly, dryness under the lens, or an infection of the cornea can all cause light sensitivity. If light suddenly bothers one eye while you wear contacts, especially with pain or redness, remove your lenses and see an eye doctor promptly.

What glasses help with light sensitivity?

Sunglasses with full UV protection, polarized lenses for glare, photochromic lenses that darken outdoors, and anti-reflective coatings can all help. Treating the underlying cause matters most; see our guide on how sunglasses protect your eyes.

What Is Light Sensitivity (Photophobia)? Causes and Relief

Q: When is light sensitivity an emergency?

Get care right away for sudden, severe light sensitivity with eye pain, redness, or blurred or lost vision, or for light sensitivity with a severe headache, stiff neck, fever, or confusion. Light sensitivity after a head injury also needs prompt medical evaluation.

If bright sunlight, overhead office lights or oncoming headlights make you squint, tear up or want to close your eyes, you are not imagining it. Light sensitivity is one of the most common eye complaints, and it ranges from a mild annoyance to something that makes it hard to work, drive or enjoy time outdoors.

The good news is that light sensitivity almost always has a cause that can be found, and many of those causes are very treatable. This guide explains what light sensitivity is, why it happens, what you can do about it, and which symptoms mean you should get care right away.

The Short Answer

Light sensitivity, called photophobia, is discomfort or pain from light levels that most people find normal. It is a symptom, not a disease. The most common causes are dry eye, migraine, eye strain, contact lens problems, and eye dilation, while infections and inflammation of the eye, eye injuries and concussion are less common but more serious. Sudden, severe light sensitivity with eye pain, redness or vision changes should be checked by an eye doctor the same day.

What Is Photophobia?

Photophobia literally means “fear of light,” but it has nothing to do with fear. It describes an unusual intolerance to light: light that does not bother other people feels too bright, uncomfortable or even painful to you. If you have seen the quiz question “an unusual intolerance to light is called ____,” the answer is photophobia.

Light sensitivity can affect one eye or both, and it can come and go or be constant. People often describe it as:

Needing to squint or close your eyes in normal indoor or outdoor light
Eye discomfort, aching or pain in bright light
Watery eyes when you step outside
Headaches triggered or worsened by light
Strong glare or halos from headlights, streetlights or screens
Preferring dim rooms and avoiding bright places

Some people notice blurred vision along with light sensitivity. That combination is worth taking seriously, because it can point to problems on the surface of the eye, such as a scratch or infection on the cornea, or inside the eye, such as inflammation.

Why Are My Eyes So Sensitive to Light? Common Causes

Dry eye

Dry eye is one of the most frequent reasons people become sensitive to light. When the tear film is thin or unstable, the surface of the cornea is less protected and more easily irritated, so bright light and glare feel harsher. Burning, grittiness and eyes that feel tired by the end of the day are common companions. Learn more in our guide to dry eye syndrome in Tennessee.

Migraine and headaches

Light sensitivity is a hallmark of migraine. Many people find bright or flickering light uncomfortable during a migraine, and for some, light can also trigger an attack. Tension headaches can cause milder light sensitivity too.

Eye strain and screen time

Long hours at a computer or phone reduce how often you blink, which dries the eye surface. Combined with screen glare and harsh lighting, this can leave your eyes tired and more sensitive to light. An outdated glasses prescription can add to the strain. See our tips on screens and eye health.

Contact lens problems

If your eyes are sensitive to light while you wear contacts, the lenses may be part of the problem. Common culprits include:

Wearing lenses longer than recommended, or sleeping in them
Lenses that are worn out, dirty or poorly fitted
Dryness under the lens
A reaction to a cleaning solution
An infection or scratch on the cornea

Light sensitivity in one eye with pain, redness or blurry vision while wearing contacts can signal a corneal infection. Take your lenses out and see an eye doctor promptly. Good habits help prevent problems; see how to take care of your contact lenses.

Eye dilation and eye procedures

Dilating drops used during an eye exam widen the pupil, letting in much more light than usual. Light sensitivity for a few hours afterward is expected, which is why sunglasses are handed out after dilation. It is also common to be more sensitive to light for a while after eye surgery or other eye procedures as the eye heals; your doctor will tell you what to expect.

Infections and inflammation

Several more serious conditions cause light sensitivity, usually along with other symptoms:

Keratitis: inflammation or infection of the cornea, often with pain, redness, tearing and blurred vision. Contact lens wearers are at higher risk.
Corneal abrasion: a scratch on the cornea, which usually causes pain, tearing and a feeling that something is in the eye.
Uveitis: inflammation inside the eye, which often causes a deep ache, redness and blurred vision along with marked light sensitivity.
Conjunctivitis (pink eye): some types cause mild light sensitivity along with redness and discharge.

These conditions need prompt diagnosis and treatment by an eye doctor.

Cataracts

A cataract clouds the lens inside the eye, which scatters incoming light. Many people with cataracts notice more glare and light sensitivity, especially from headlights at night.

Concussion and other medical causes

Light sensitivity is a common symptom after a concussion or other head injury, and it can linger during recovery. It can also occur with some viral illnesses, neurological conditions, and as a side effect of certain medications. Rarely, it is a sign of a serious condition such as meningitis.

When Is Light Sensitivity an Emergency?

Get care right away, the same day, if light sensitivity comes with any of the following:

Sudden, severe light sensitivity with eye pain
A red, painful eye, especially in a contact lens wearer
Blurred vision or loss of vision
A chemical splash, injury, or something stuck in the eye
A severe headache with a stiff neck, fever, confusion or vomiting
Light sensitivity after a head injury

For the eye symptoms, call your eye doctor promptly. For a severe headache with stiff neck or fever, confusion, or symptoms after a head injury, go to an emergency department.

How to Relieve Light Sensitivity

The most effective relief comes from treating the underlying cause, such as dry eye, an infection or an outdated prescription. While you are working on that, these steps can make light more comfortable:

Wear good sunglasses outdoors. Choose lenses that block UV rays (here is how sunglasses protect your eyes). Polarized lenses cut glare from water, pavement and car hoods.
Consider photochromic lenses. These darken automatically in sunlight and clear indoors.
Ask about anti-reflective coatings on your glasses to reduce glare from screens and headlights.
Wear a brimmed hat to shade your eyes from overhead sun.
Adjust your lighting. Use softer, indirect lighting at home and work, dim your screens and turn on dark mode where it helps.
Use lubricating eye drops if dryness is a factor, and take regular screen breaks using the 20-20-20 rule: every 20 minutes, look at something 20 feet away for 20 seconds.
Give your contacts a break if light sensitivity started while wearing them, and wear glasses until you have been checked.
Avoid wearing dark sunglasses indoors all the time. It can feel good, but over time it may make your eyes even less tolerant of normal light. Talk with your eye doctor about the right balance.

When Should You See an Eye Doctor?

Even if your symptoms are not urgent, it is worth booking an eye exam if:

Light sensitivity is new, getting worse, or lasts more than a few days
It affects your work, reading or driving
You notice blurred vision, frequent headaches, or more glare at night
You wear contacts and light has started to bother you

During an exam, your eye doctor will look closely at the surface of your eye, your tear film and the inside of your eye to find the cause. Treatment depends on what is found and may include dry eye care, a prescription update, a lens change, or medication for infection or inflammation. If your light sensitivity is linked to migraine or another medical condition, your eye doctor can help coordinate care with your primary care doctor.

Get Help for Light Sensitivity in East Tennessee

Tennessee Eye Care evaluates and treats light sensitivity through our medical eye care services at clinics in Harriman, Knoxville, Lenoir City, Morristown and Powell. If light has been bothering your eyes, find a location near you and schedule a visit.