Concept:The cornea is the transparent, outermost layer of the human eye, composed of proteins and cells, and lacks blood vessels.
Explanation:The cornea is a thin, clear membrane at the front of the eye through which light enters.
It is not a light-sensitive screen; the retina performs that function.
It is not a muscular diaphragm; the iris controls pupil size.
Unlike most body tissues, the cornea does not contain blood vessels.
It is made up of proteins and cells, which maintain transparency.
Thus, the correct description is that the cornea is composed of proteins and cells.
Answer:Option D: is composed of proteins and cells.
