Why the colour of our eyes can change as we age

Several factors may influence the darkening or lightening of eyes as time passes. Source: Getty Images.

As we grow older, a number of changes happen to our bodies. While the obvious external signs are hair turning grey and skin becoming wrinkly, it’s also possible for our eyes to change colour.

Eyes are one of the most complicated organs in the body behind the brain. As we age, the quality of our eyesight deteriorates and, for some people, the colour can also change. In fact, All About Vision suggests that a change in eye colour occurs in up to 15 per cent of all Caucasian people throughout their lifetime. While these changes usually occur in people with lighter eye colours, a number of other factors can contribute to eyes becoming darker or lighter over time.

A change in emotion is one of the ways your eyes can change colour. Pupil sizes are known to be influenced by the hormones the body releases when a change in mood is triggered by being happy, sad, or angry. It’s believed that stronger emotions like anger and happiness can cause your eyes to appear more dynamic, while crying can cause your iris to appear shinier than it really is. As your pupil changes size, the pigments in the iris compress and expand causing the colour to change slightly.

Another factor is sun exposure. Just as your skin changes in the sun, melanin in the eye can also be influenced through the sun’s rays. If you spent a lot of time in the sun, you’d likely notice the colour of your eyes becoming darker. It’s always important to protect your eyes with glasses if you’re spending prolonged time in the sun.

Your diet can also be a contributing factor. Nuts, onions, fish, honey and even spinach all have the potential to change your eye colour.

Having said that, a 2005 report by The New York Times suggests that changes are quite rare and that eyes will rarely change without reason. Eye colour is usually determined in infancy and usually doesn’t change unless affected by certain medical conditions.

Heterochromia is a condition that causes the colour of each eye to be completely different, or even for one iris to have several different colours. While it’s entirely possible to be born with the condition, it usually occurs later in life as the result of trauma to the eye. This could include an injury or accident, surgery, extreme swelling, just to name a few. The condition affects around 1 per cent of the entire population, meaning it’s quite rare.

Pigmentary glaucoma is an inherited type of glaucoma that is more likely to impact men than women. It can gradually impact eyesight, with most people first noticing something isn’t quite right in their 30s or 40s. It usually occurs when pigment cells begin to float around the eye, but can be rather damaging when it impacts the optic nerve. Other research has pointed at simple genetics.

IMPORTANT LEGAL INFO This article is of a general nature and FYI only, because it doesn’t take into account your personal health requirements or existing medical conditions. That means it’s not personalised health advice and shouldn’t be relied upon as if it is. Before making a health-related decision, you should work out if the info is appropriate for your situation and get professional medical advice.

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