If it seems your eye colour is not as vivid as it once was, you’re probably not just imagining it.
The top layer of the iris — or stroma — contains melanocyte cells which make granules of the brownish pigment melanin.
The more pigment is produced, the darker the eye colour.
However, over time the number of these pigment-making cells can start to dwindle, and the ones that are left also produce less pigment. People with green or blue eyes will notice the most fading, usually by their 50s.
Those with brown eyes — who still have a high concentration of melanocytes — will see the least change.
Glenn Carp, an eye surgeon from the London Vision Clinic, says that around 5 to 10 per cent of people will notice their eyes subtly fade in hue.
‘In most cases, it will be very gradual and only noticeable if you compare old photographs with more recent ones.’