Night shine heterochromia

pics@lemmy.world – 174 points – 7 months ago

In the light, my dog has 2 browns eyes, but the shine at night is 1 red and 1 green. Merry Christmas from Dinah-dog!

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This is due to a structure in the back of the eye called the tapetum lucidum. This is a reflective layer in the back of the eye that sits just in front of the blood filled layer called the choroid. The job of this layer of the eye is to reflect light back onto the retina a second time to amplify light in dark conditions. The color of the tapetum and its reflection can vary from a green, blue, orange or yellow hue. This coloration often changes over the first 3 months of life. Some dogs, similar to humans, do not have a tapetum. This is most common in dogs with blue eyes. Thus, when a photograph is taken, the tapetum is not present to create the colored reflection and therefore the red blood vessels in the back of the eye are visualized. This creates the “red eye” look.

Interesting. So your dog is night blind in one eye?

If you notice a change in how your dog’s eyes are reflecting over time (duller or brighter) or there is a difference in the reflection between eyes, it is advisable to have the eyes examined. It could indicate an eye disease that needs to be addressed.

Hmm. Nah.

That last bit goes for people too, it's called Leukocoria can be am early sign of all sorts of eye disease. It's a common way retinoblastoma (a thankfully relatively rare child eye cancer) gets caught - it shows up as a sort of white sheen in one eye in flash photos.

I know someone who had that. I remember their parents explaining how "red eye", in photographs, meant a healthy eye and how their child had had a "green eye" which lead to the path of the initial diagnosis.

They are a healthy young adult now with a glass eye.