Cat eyes

Not sure if this is considered genetics or not.. but does eye color determine cat's vision?

I have one cat who's eyes are unique (in my avatar).. not the common gold or green, it's more like a glow-in-dark green color (for lack of better description)
My vet says she's hard of seeing in one eye, but I don't see it.

Howdy ho Cat Lovers,

Eye color is actually complex genetics, being controlled by more than one gene.  One major gene is Tyrosinase (TYR) that controls the Siamese and Burmese colorations of cats.  Cats with mutations in this gene will have blue eyes when having two copies of the Siamese mutation (and also siamese coloration) and Burmese with have a more greenish color, while Tonkinese is kind of aqua.  The Siamese mutation also affects what is called the "optical chiasma (cross)", the nerves that go from the left eye to the right brain and the right eye to the left brain.  Siamese sometimes have poor a optical chiasma and could have depth of field issues.

If cats have excessive "eye shine" - the reflection of the tapetal layer in the back of the eye - what makes animals eyes glow at night - this could be a vision problem.  Cats with blue eyes have a red eye shine while cats with darker colored eyes have a greenish eye shine.  This is normal and there are no associated vision issues.

This cats eyes are an interesting coloration, however, by itself, does not indicate a vision issue, especially if only in one eye.  Inherited issues occur in both organs when you have two - bilateral organs, such as eyes and kidneys.