Rating Newest Oldest. Best Answer: It's part of the nervous system as it is literally an outgrowth of the frontal cortex of the brain. The eye is formed during embryonic development by a combination of head ectoderm and neural tube tissue, the latter forming the retina.Thus, the retina is not a peripheral sensory organ ... but rather it is an outgrowth of the central nervous tissue. Because of this origin, the retina ...he eye is formed during embryonic development by a combination of head ectoderm and neural tube tissue, the latter forming the retina. Thus, the retina is not a peripheral sensory organ ... but rather it is an outgrowth of the central nervous tissue.