Photophobia: why some eyes struggle with light

Eye health, 5 min read, August 2026

Some people squint the moment they step outside, while others never reach for sunglasses. This is neither fragility nor habit, and it has an explanation.

Photophobia means abnormal discomfort in light that the people around you handle without difficulty. It ranges from mild discomfort, squinting in the sun, to real pain, with watering eyes and the need to retreat into the shade. It is not a diagnosis in itself, it is a symptom, and its cause decides what to do about it.

What happens inside the eye

The iris, the coloured part, works like a diaphragm. It contains a pigment, melanin, which absorbs part of the light that does not come through the pupil. The darker the iris, the more it absorbs. A blue or green iris holds less melanin, lets more diffuse light through its thickness, and the eye therefore receives more stray light.

That is why people with light eyes are statistically more bothered by the sun. It is not an impression, it is optics. The same logic applies to albinism, where the absence of pigment often produces significant photophobia.

The common causes

Dry eye. This is by far the most ordinary cause, especially in hot climates, under air conditioning or on a scooter. An irregular corneal surface scatters light instead of transmitting it cleanly, which produces halos and glare.

A correction not worn, or not strong enough. An eye that strains constantly becomes more sensitive to everything, light included. This is particularly true of uncorrected astigmatism, which creates rays around light sources.

Migraine. Photophobia is a central sign of a migraine attack, often present before the pain itself. It can persist between attacks in chronic migraine sufferers.

Fatigue and lack of sleep. They lower the tolerance threshold, without anything being wrong with the eye at all.

Certain medications. Several common treatments dilate the pupil or increase sensitivity to light. It is a cause that often gets forgotten, and it is easy to check on the leaflet.

Ophthalmological causes that need an opinion. Inflammation inside the eye, corneal damage, recovery from surgery. These are the situations where waiting is not an option.

"Long standing, stable photophobia can be managed. Photophobia that appears within a few days needs to be examined."

The signs that call for a prompt consultation

Sensitivity that sets in abruptly, a red and painful eye, a drop in vision, heavy watering, a persistent feeling of something in the eye, or photophobia affecting only one eye. In all of these cases it is not simple discomfort and an examination is needed.

What helps day to day

Genuine sun lenses, certified UV400, category 3. The goal is to cut brightness while filtering UV. A tint with no filter makes the problem worse, exactly as with children.

A frame that covers. A large share of the light that bothers you arrives from above and from the sides. A wide, slightly curved lens changes more than a darker tint does.

Brown or amber tints. They increase contrast and are often better tolerated by sensitive people than neutral greys at the same level of brightness.

Treating dryness if it is there. Artificial tears, screen breaks, keeping out of the direct flow of the air conditioning. Once the eye surface becomes regular again, glare drops noticeably.

Not over protecting. It is counter intuitive but documented: wearing very dark lenses indoors, all the time, increases light sensitivity over time. The eye adapts to the low level and tolerates the normal level less and less. Sunglasses are for outdoors.

The case of photochromic lenses

They darken under ultraviolet and clear up indoors. For a sensitive person walking in and out all day, that is real comfort. One limit worth knowing: most of them activate poorly behind a car windscreen, which already filters UV. For driving, a dedicated pair of sunglasses remains more effective.

Have your sensitivity assessed: free eye exam with our optometrists, details on Free Eye Exams in Bali.

This article is informative and does not replace medical advice. Light sensitivity of recent onset, or associated with pain, must be examined without delay by a healthcare professional.