Light sensitivity also known as photophobia, often affects people who have an underlying eye condition.

Good lighting can help you make the most of your sight, particularly if you have an eye condition that is affecting your vision. However, for some people, everyday lighting conditions can seem too bright, causing them discomfort and this can even affect their quality of vision. Light sensitivity can increase when you have an eye condition, but it can also be caused by some general health conditions. For some people with light sensitivity, there can be no known medical cause. Whatever the underlying cause, reducing the amount of light entering the eye can still help to relieve the symptoms of light sensitivity.

What causes light sensitivity?

Light sensitivity is often worse when you have an eye condition. This might be because there is inflammation (swelling) affecting part of your eye. There are some eye conditions that cause your eye to adapt more slowly to changing light levels, and this can make you more light sensitive in these situations. Your eye condition may cause changes that mean light is scattered inside your eye instead of reaching the macula as it should. This light scatter causes glare which can increase your sensitivity to light.

Other causes of light sensitivity include some medications, migraine and some general health conditions. Some people are more light sensitive without having any underlying medical cause.

What is glare?

Sometimes the lighting around us interferes with our vision. When lighting makes it uncomfortable for you to see or makes your vision worse, it’s known as glare.

Glare can be a problem if a light is too bright for you, it’s coming from the wrong source, or it isn’t in the right place. There are two types of glare that can cause problems - discomfort glare and disability glare. For some people, both can be present at the same time in certain circumstances.

What is discomfort glare?

Discomfort glare occurs when a light source is just too strong for our eyes. It may cause us to “screw up”, shade or even close our eyes because the light level makes you feel uncomfortable. When trying to see in these bright conditions, however, discomfort glare doesn’t usually make your vision less clear than it was before.

What is disability glare?

Disability glare occurs when a light source reduces how well we can see, and the brighter the light is, the more glare it can cause. Some eye conditions cause disability glare, not only in bright lighting, but with everyday lighting as well.

Disability glare doesn’t necessarily cause discomfort, but it can reduce how much detail we can see. This type of glare generally reduces contrast, so that objects aren’t as easy to see against their background.

What eye conditions can cause light sensitivity and glare?

Many eye conditions can cause light sensitivity and glare, some examples include:

• Coloboma - where the lower portion of some eye tissues is missing
• Ocular albinism – this is when some people are born with a lack of pigment in the eye.
• Aniridia – a condition where the iris is missing from birth.
• Cataracts – clouding of the lens inside the eye.
• Macular degeneration – a condition affecting the macula, the area in the eye responsible for our central, detailed vision.
• Uveitis – inflammation inside the eye.
• Inherited retinal dystrophies such as retinitis pigmentosa.
• Corneal dystrophies which cause changes in the cornea..
• Glaucoma - the pressure inside the eye is too high, causing damage to the optic nerve at the back of the eye.
• Keratoconus – where there are changes in corneal shape, strength and thickness.

What should I do if I have light sensitivity and glare?

It’s important to see an optometrist (optician) if you are sensitive to light, so they can examine your eyes. An optometrist will be able to check the health of your eyes and look for any underlying eye condition which could be causing your light sensitivity or issues with glare.

If you suddenly become sensitive to light or your light sensitivity worsens, you should have your eyes checked as soon as possible, as it can indicate that an eye condition has become worse or that a new condition has developed. Much less commonly, more severe light sensitivity that starts very quickly can be the first sign of a serious condition such as meningitis. If you are in any doubt, it is always best to have any new symptoms checked by a doctor or optometrist.

Can light sensitivity or glare be treated?

If your light sensitivity is being caused by an underlying eye condition, your symptoms can improve if the eye condition can be treated. Treating eye conditions like uveitis often means that your eye becomes less light sensitive.

Unfortunately, not all eye conditions can be treated, but there are still things that can help you cope better with any light sensitivity and glare they cause.

How can I manage light sensitivity and glare?

The best way to manage light sensitivity and glare is to limit the amount of light entering your eyes. This can be done by shading them with your hand, wearing a baseball cap or a wide brimmed hat, or shading beneath an umbrella or parasol. Wearing sunglasses or tinted eye shields is often helpful too, and your optometrist or low vision specialist will be able to advise you further about the lens types that may work best for you.