We can observe a phenotype whether or not we understand the genetics behind it. In real life, there is a gene called HERC2 that works like I described, and most people with blue eyes have the broken allele of this gene.
Nerves, Neuroglia, and Ganglia. A nerve is a bundle of fibres (axons and/or dendrites) outside the CNS. Neuroglia are cells of the nervous system that help protect and support it. Ganglia are groups of nerve cell bodies lying outside the CNS.
What is the medical term meaning destruction of a nerve? Neurolysis is destruction of a nerve or nervous tissue. Neuropathy, in contrast, means any disease of a nerve or nerve tissue.