Why are my eyes sensitive to light? Photophobia causes and what helps

Have you noticed that light bothers you more than it used to? It might be morning sunlight that makes you squint the second you step outside, or office lighting that gives you headaches and leaves you feeling drained. 

The medical term for this is photophobia, and it's more common than most people realise. For some people, the sensitivity is a mild, background irritation on bright days; for others, it's sharp enough to make keeping their eyes open difficult and interfere with everyday life. 

It can be hard to know exactly what to do about it, too. Is this something an optometrist or a GP should look at? Should you wait and see if it passes, or is it worth mentioning now? That uncertainty can be as frustrating as the symptoms.

Photophobia isn't a diagnosis of a condition in itself. Something else will be causing the symptoms you’re having, whether that's dry eye, migraine, surface irritation or, less commonly, inflammation inside the eye. The good news is that most causes can be identified and treated. This guide aims to help you understand what your symptoms mean and when professional advice is needed. 

What does it mean if your eyes are sensitive to light?

Despite what the name suggests, Photophobia describes an increased sensitivity to light, rather than a fear of it. Light passes through several structures on its way into the eye, from the tear film and cornea at the front, to the retina at the back. A problem at any point along that path can make normal brightness feel uncomfortable or painful.

What that problem looks like depends on where it sits. When the tear film becomes unstable, the surface of the eye becomes irregular, and the corneal nerves become more sensitive, which can make normal light levels feel uncomfortable.

The cause might sit on the surface of the eye, or it could involve deeper structures or even the nervous system. Each produces a different pattern of symptoms, and recognising yours is usually the most useful starting point. When the sensitivity occurs and what else accompanies it, particularly pain, redness or changes in vision, helps narrow down the specific issue.

Quick self-check: what pattern matches your symptoms?

Sensitivity to light often has recurring, consistent patterns or triggers. We’ve listed the most common patterns below to help you quickly self-assess and see if any of these feel familiar to you.

Only in bright sunlight

If discomfort mainly happens outdoors, your eyes are probably reacting more strongly to glare than they should be. Reflections off water, roads or glass tend to make it worse. Some eye conditions, such as cataracts or corneal irregularities, cause light to scatter within the eye rather than reaching the retina cleanly, making your eyes more sensitive to glare than they would usually be.

Polarised sunglasses and a brimmed hat can make a noticeable difference in reducing this discomfort when you're outside. If glare is affecting your confidence when driving or your vision seems reduced, it's worth booking an eye examination.

Worse with screens or fluorescent lighting

If screens or strip lighting bother you more than natural light, dry eyes might be the cause. The problem tends to get worse with prolonged screen use or in air-conditioned environments.

Adjusting screen brightness and taking regular breaks can both help, and using preservative-free lubricating drops often makes a noticeable difference, too. If your eyes still feel gritty, red or strained most days, it's worth arranging an assessment.

Comes with headaches or nausea

Light sensitivity that arrives alongside a headache is frequently linked to migraine. Exposure to light can worsen the pain, or you might find that sensitivity begins before the headache develops. If the pattern matches previous episodes, migraine is a likely explanation.

If you experience a sudden, severe headache with new light sensitivity that feels different from anything you've experienced before, it should always be assessed urgently.

Only one eye is affected

If sensitivity to light affects only one eye, particularly if it is accompanied by pain, redness or blurred vision, it should be assessed promptly. Unilateral photophobia can sometimes indicate inflammation inside the eye or corneal problems that require treatment. This is more likely to be the case if you’re also experiencing redness, pain or blurred vision. It's worth getting checked promptly, rather than waiting to see if the discomfort settles.

If the symptoms are sudden and severe

If you experience sharp pain or any change in vision along with light sensitivity, seek urgent medical advice. These symptoms can point to inflammation inside the eye or other conditions that need rapid treatment.

What are the most common causes of light sensitivity?

Once the patterns around your light sensitivity are clear, it’s easier to try to understand the root cause of your Photophobia. In this section, we’ll cover what these causes might be and how they happen.

Dry eye and surface irritation

The natural tear film in your eye acts as a smooth optical surface. When it becomes too thin or breaks up too quickly and spreads unevenly, light scatters across the front of the eye instead of passing through cleanly. That scattering is what makes brightness feel harsher than it should.

Dry eye tends to be worse in air-conditioned or heated rooms due to lower humidity. It’s also often worse following lengthy screen use towards the end of the day.

The initial treatment is preservative-free lubricating drops, which help to stabilise the tear film. Alongside this, you should also consider adjusting your environment, taking breaks from computer or phone screens and managing humidity levels if possible. 

If you’re still experiencing issues after taking the drops and making adjustments to your environment and routine, a more detailed assessment is worthwhile. 

Migraine and neurological causes

Migraines change how the brain processes sensory input, including light. Brightness that’s usually tolerable can become painful during an episode. The sensitivity can begin during the aura phase, before the headache itself arrives.

Most people who experience migraines will recognise the pattern. The sensitivity builds alongside the headache, or just before it. Often this is combined with nausea or visual disturbance, and this fades as the episode passes. It’s possible to reduce how often they occur if you’re able to recognise and keep track of the triggers, including lighting conditions. 

Even if you have a history of migraine, if you experience a new type of headache triggered by light, you should seek medical advice just to be sure. 

Other possible causes

In some cases, light sensitivity may be linked to less common eye or neurological conditions, including:

• Corneal abrasion, where the surface of the cornea has been scratched or injured
• Acute iritis, a form of inflammation affecting structures inside the eye
• Angle-closure glaucoma is a rare but serious condition that can cause sudden eye pain and vision changes
• Retinal migraine, which can temporarily affect vision and increase sensitivity to light
• Blepharospasm, where involuntary eyelid spasms make light feel more uncomfortable
• Albinism is a genetic condition that can affect how the eye processes light.

Most people with light sensitivity don’t have one of these conditions. Although these causes are uncommon, persistent light sensitivity, severe pain or changes in vision should be assessed with an eye examination.

Common causes of eye inflammation: Uveitis, Keratitis and Conjunctivitis

If your eye is inflamed, you’re likely to experience a different type of sensitivity to light. Rather than causing discomfort, exposure to light might trigger more of a deep aching sensation. It’s this difference that helps signpost that inflammation is the cause rather than dry eye or migraines. 

Uveitis is when the middle layer of your eye becomes inflamed. Alongside a sensitivity to light, symptoms can include red, watery eyes, a deeper sensation of pain and flashes and floaters. It can lead to long-term complications and will require treatment, which means you should seek advice from an ophthalmologist if you have any concerns.

Keratitis is an inflammation of the cornea - the clear surface of the eye. It could be caused by infection or non-infectious injuries. It can cause intense eye pain, the sensation that something is in your eye, and sensitivity to light. Keratitis can progress quickly and should be assessed urgently within 24 hours of experiencing Keratitis symptoms, particularly in contact lens wearers. It can develop quickly and cause corneal damage if left untreated.

Conjunctivitis is a condition caused by allergies or infection. The most common symptoms are red, itchy eyes that produce sticky pus. Sensitivity to light here is usually mild, especially compared to Uveitis and Keratitis, but still uncomfortable. Mild conjunctivitis often settles with simple measures such as lubricating drops and good eyelid hygiene. Avoid wearing contact lenses until the symptoms resolve. A pharmacist or optometrist can advise if treatment is needed.

Corneal problems and contact lens irritation

The cornea is the eye's main focusing surface. A scratch, infection or irritation caused by overworn contact lenses can make it hard to tolerate even moderate light. The pain is often sharp and localised, and will often affect one eye more than the other.

Alongside light sensitivity, you might experience watering, redness and, similar to Keratitis, the lingering feeling that something is in your eye. It’s important to remove your contact lenses if you suspect this is happening, and contact your optometrist for an assessment.

Medication-related sensitivity

There are some medications that list photophobia as a side effect. These include tetracycline antibiotics, some antidepressants, diuretics and antihistamines. If your sensitivity to light began soon after starting a new medicine, raise this with your GP or pharmacist before stopping or changing how you take your medication yourself.

After eye procedures or dilation

If you’ve had your pupil dilated for an eye examination or a procedure, you’re like to have experienced light sensitivity afterwards. Dilating drops widen the pupil, letting more light into the eye than it normally would, which causes the discomfort. Depending on the reason for the dilation, this usually settles within several hours, although some people notice mild sensitivity for a day or two. 

If you find the sensitivity continues longer than this after pupil dilation, check with your practitioner that healing is progressing as it should.

What helps with light sensitivity? Practical steps you can take

It’s almost impossible to avoid light entirely if you’re experiencing sensitivity, so the most practical steps you can take are ones to help you avoid unnecessary strain. These are small adjustments to your daily life that can help to reduce your discomfort whilst the underlying cause is being identified or treated. 

Outdoor glare

The most effective step you can take to address outdoor sensitivity is to wear sunglasses that block 100% of UVA and UVB rays. Choosing a pair with polarised lenses can also help reduce glare from reflecting surfaces. 

You should also consider wearing a brimmed hat that can keep direct overhead light out of your eyes. 

Indoor glare

Fluorescent strip lighting is one of the most common triggers for indoor light sensitivity. If the lighting in your workplace is causing issues, you’re within your rights to request that they make reasonable adjustments - and this includes looking at office lighting and moving your workstation away from any particularly bright overhead lights. Try to position yourself so that light sources are slightly behind your desk rather than directly overhead or in front of you. 

Screen habits

If your daily work involves a lot of screen time, changing the settings on your monitor can make a real difference. Try lowering the screen brightness so it roughly matches the surrounding room, and increase the text size to reduce eye strain.

Make sure you also give your eyes brief breaks from screen time. These short breaks every 20 to 30 minutes allow the tear film in your eye to stabilise, reducing the surface irritation that makes light feel harsh.

Supporting the tear film

Using eye drops can help restore a more stable surface layer and quickly improve comfort. You can get preservative-free lubricating drops over the counter at most chemists. 

Alongside using drops, trying to influence the direct environment around you can make a real difference. If you can, try to turn down the air conditioning and avoid sitting directly under heating vents.  

Tracking patterns

Keeping notes on when your sensitivity to light is triggered can help to reveal patterns and causes. It’s worth the extra effort to record the time of day, lighting environment, screen use and whether a headache accompanies the sensitivity. Identifying migraine triggers supports longer-term management, so tracking patterns is especially helpful if migraine is suspected.

When should you see a doctor or optometrist?

You should book an eye assessment if photophobia happens at the same time as vision loss or significant pain. The same applies if your eyes are visibly red when they weren’t before, or if you have any headaches that don’t fit any previous patterns

You should also pay close attention to how long your sensitivity continues for. If it lasts more than a few days or is getting noticeably worse, it’s time to get assessed.

During an assessment, your optometrist can thoroughly examine your eyes for signs of inflammation, surface issues and irritation, or deeper structural issues. It can feel reassuring to have any more serious conditions ruled out and to know that you’ll be recommended treatment as early as possible if required when you're assessed. 

Key takeaways

Experiencing sensitivity to light can feel unsettling, especially if it comes on suddenly or hasn’t happened before. The good news is that most of the time, the cause is identifiable and manageable once it has been properly assessed. 

Managing your Photophobia symptoms can be relatively straightforward: 

Stabilising the tear film, reducing glare, adjusting screen habits or managing migraine triggers can all considerably ease your symptoms. When the cause is inflammation or other underlying eye conditions, getting treated early can help you avoid unnecessary discomfort and protect your long-term eye health. 

The most important thing to look out for with light sensitivity is changes. If your eyes are reacting differently to light than they usually do, pay attention to these changes. Even if your symptoms are mild at first, getting an eye examination will reveal what’s causing your Photophobia and put you back on the path to feeling comfortable again.