Its most likely incubation than genetic.
Sometimes when there's an abnormal temp spike, for example, it sometimes results in eyeless or one eyed snakes. So having an abnormal small eye wouldn't surprise me if that was the case. Not to mention snakes that are genetically prone to eye issues are BELs.
Either way, your snake sounds healthy. I wouldn't think much of it.
Sent from my DROID RAZR using Tapatalk 2