Bill Harvey: Oh, you’ve got green eyes
When asked about the colour of a child's eyes, I realised that I was on shakier ground
Author: Bill Harvey
Insulted at being called a Guardian-reading, tofu-eating wokeratus (or wokerato, if you want to be modern), I recently took some time off to play with the latest addition to the Harvey clan.
I felt reasonably confident answering many of the questions asked by the parents of one month old Jax. Yes, it is quite normal in the first few weeks to see the eyes occasionally look in different directions. Yes, he can see objects close up, but might easily be distracted by a bright object much further away in the periphery. No, don’t worry yet if he does not seem to be able to track an object – this should kick in very soon.
When asked about the colour of his eyes, however, I realised that I was on shakier ground. Eye colour and its determination is a very complex area, one governed by as many as 16 genes with variable expression. In fact, the one statement that can be confirmed is that it is not true that all babies start with blue eyes that get darker in the first weeks of life. And while the concentration of melanin deposited on the back of the iris will dictate the colour, its distribution will also influence the way light is scattered to create the unique hue of each individual. Also, melanin deposition in the first two years is highly variable. One recent study of over 200 infants over their first two years of life found 27% changed from blue to brown, 7.5% from blue to hazel and 5% from blue to green.
Finally, if you enjoyed the recent paper on what causes rechecks and how to avoid them (Optician 22.07.2022), you might want to support further work by the same research team that are looking at the refraction styles of UK optometrists. To take part, go to: tinyurl.com/refmethod.
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