BULGE EYES:

The cornea of the eye bulges out without significantly affecting the vision, although this is not tested by more than casual observation.
In selected matings that I made, one mating yielded 5 bulge eyed offspring out of 30 total, and the other mating yielded 2 bulge eyed offspring out of 20 total. This would lead one to postulate a recessive mutant. However, when two bulge eyed parents produced two normal nest mates simple recessive inheritance was excluded.
This character was brought to my attention by Troy Berndt in Wisconsin.