Eyes

"The eye is the organ of sight (vision) in humans and animals. The eye works by transforming light waves into visual images. Eighty percent of all information received by the human brain comes from the eyes. Eye color is created by the amount and type of pigment in the iris. Multiple genes inherited from each parent determine a person’s eye color. The eye is a slightly asymmetrical globe, about an inch in diameter. The front part of the eye (the part you see in the mirror) includes:
• The iris (the pigmented part)
• The cornea (a clear dome over the iris)
• The pupil (the black circular opening in the iris that lets light in)
• The sclera (the white part)
• The conjunctiva (an invisible, clear layer of tissue covering the front of the eye, except the cornea)"

Retrobulbar fibroplasia

Retrobulbar fibroplasia also known as retinopathy of prematurity (ROP), is a rare disease in which blood vessels grow abnormally behind the retina. In severe cases, this progresses to scar tissue which can lead to problems with the eye. Retrolental fibroplasia occurs in premature infants and has been linked to the high concentrations of oxygen used to support their underdeveloped lungs.