Bug eyes are also a problem in some lines of leucistic Texas rat snakes. And small and missing eyes seem to turn up in Kahl albino boa constrictors more often than in normals.

There is a mouse gene named microophthalmia that produces eye abnormalities. On the other hand, small and missing eyes are a congenital abnormality in pigs that are vitamin A deficient. I am not convinced that eye abnormalities in snakes are entirely due to genetics. IMO, more study is needed.