I have been fascinated by my cat’s eye colour. Sometimes they are intense, and sometimes the colour changes. So I researched to find out why!
Like human eyes, cats' eyes look different in sunlight vs dim light. The tapetum lucidum, which is the reflective layer in their eyes, gives that glowing effect at night and can affect how their eye colour looks.
And all kittens are born with blue eyes, but around 6 to 8 weeks, their eye colour begins to change as melanin develops. This fact actually tricked me as I named my cat 'Blue' when he was a kitten due to his very blue eyes, but then it lightened and turned to a blue-green so we changed his name to Blu :))
If the cat is excited, scared or hunting, their pupils dilate, which can make the iris look darker and more intense.
And in calm or bright moments, their pupils shrink and more of the true eye colour becomes visible.
Also, the amount and type of melanin in a cat's iris determine the eye colour. Low melanin gives them blue eyes, moderate melanin gives them green, golden or hazel eyes, and high melanin gives them copper or amber eyes.
But then I wondered, as my cats are black and full of melanin, why one has light eyes, then I found out that their melanin in the eyes is separate from their fur colour, so it depends on their unique gene mix.
And the amazing fact is that colour in cats’ eyes are from the amount of melanin they actually have no colour pigment but it is from the light scattering which is called the Tyndall effect, similar to the the sky looks blue, so that is what we are sensing, the colour is from how the light reflects and scatters inside the eyes not from colored pigment.
And the special structure behind their retina that I mentioned earlier, called tapetum lucidum, reflects light back into their retina, and that gives them night vision and makes their eyes glow in the dark, which gives them that mystical shine!
Some interesting information below if you want to understand more!
References:
https://cattree.uk/understanding-cats-night-vision-eyesight/
https://basepaws.com/blog/the-peculiar-case-of-cat-eye-colors
https://www.thecatsmeowrescue.org/blog-feline-friends/cats-eye-colors-explained
https://www.petscare.com/news/post/understanding-cat-eye-colors
https://en.wikipedia.org/wiki/Tapetum_lucidum
Have a lovely day!
Mariah 😺💖