Have you ever wondered why are green eyes more sensitive to light than darker eyes?
Light sensitivity, known as photophobia, is common, and people with lighter coloured eyes often notice it more. The colour of your iris affects how much light reaches the back of your eye, which is why eye colour and light sensitivity are connected.
Photophobia happens because of the connection between the light-detecting cells in your eyes and the nerve pathways that carry those signals to the brain.
What makes green eyes more sensitive to light is the amount of pigment in the iris.
Lighter coloured eyes have less melanin, the pigment that gives eyes their colour. Melanin acts like a filter, so when there is less of it, more light passes through to the back of the eye. Someone with green or blue eyes will typically have more light reaching the retina than someone with dark brown eyes, where more of it is absorbed. People with brown eyes can still be bothered by bright light, but usually less severely. ← replace this paragraph
Green eyes are the rarest eye colour, occurring in roughly 2% of people worldwide, and green-eyed people often report the most light sensitivity. Blue-eyed people also commonly experience photophobia, generally with slightly fewer symptoms.
Green eyes are most common in Northern Europe, where daylight levels are lower. The colour is also a favourite in pop culture, with Harry Potter, Mary Jane Watson and Rapunzel all sporting prominent green eyes.
Light sensitivity has many possible causes beyond the colour of your iris:
An unstable tear film scatters light across the eye surface, which increases glare. This is one of the most common causes, and often the most treatable.
Light sensitivity is so common in migraine that it forms part of the diagnostic criteria.
Photophobia is one of the most frequently reported symptoms after a head injury, and it can persist well beyond the others.
When the eyes struggle to work together, bright or visually busy environments become harder to tolerate.
Cataracts, corneal abrasion, conjunctivitis, keratitis, eye allergies and macular degeneration can all cause light sensitivity.
Some medications list light sensitivity as a side effect. It is worth mentioning any new medication at your appointment.
If your light sensitivity is persistent, has come on suddenly, or comes with eye pain or redness, it is worth having it assessed rather than assuming it is just your eye colour.
Sensitivity or aversion to light
Difficulty reading or looking at text
Pain or discomfort when looking at light
Squinting one or both eyes
Forehead pain
Watery eyes
Wanting to keep your eyes closed
If your light sensitivity is simply down to having lighter coloured eyes, it is not something that gets cured, but it is very manageable. Where there is an underlying cause such as dry eye, treating that often improves the sensitivity considerably.
Everyday things that help:
Give your eyes time to adjust when moving between areas with different light levels
Shield your eyes from the sun outdoors, including with a hat
Wear polarised sunglasses to cut glare and protect against eye sunburn
Consider wrap-around styles, which stop light entering from the sides
FL-41 filters blue-green light, around 480 to 520 nanometres, which is the range most often linked to light-triggered discomfort. Blocking those wavelengths can also improve contrast, which some people find makes vision feel sharper. It is the most researched tint for light sensitivity, particularly where migraine is involved.
Beyond FL-41 there is a wide range of medical filter tints, and the one that helps varies from person to person. We trial them in clinic so you can see which eases your symptoms before anything is prescribed.
If your photophobia is related to dry eye, lubricating drops such as Hylo-Forte or Systane can reduce discomfort. Ask us which suits your particular dry eye pattern.
Light sensitivity is easy to write off as just the way your eyes are, particularly if you have always had lighter coloured eyes. But if it is affecting your work, your driving or your comfort day to day, it is worth finding out whether something treatable is behind it.
