Eagle eyes are 4-8 times stronger than human eyesight. Eagle eyes are about same size as human eyes but flatter back. Eagle eyes are larger than their brain by weight. Eagle eyes can spot rabbits 3.2 kilometers away
Thin muscle located near anterior margin of orbit floor. Originates from maxillary bone lateral to lacrimal groove. About 35 mm long in humans. Inserts onto scleral surface between inferior and lateral rectus
Smooth muscle running radially in iris. Consists of modified myoepithelial cells. Contracts to widen pupil for better light entry. Works in opposition to pupillary constrictor
Ciliary muscle forms ring of smooth muscle in eye's middle layer. Develops from mesenchyme within choroid as cranial neural crest derivative. Contains circular, longitudinal and radial fiber orientations
Vitreous body fills space between lens and retina, making up 4/5 of eyeball volume. Transparent, colorless gel surrounded by collagen vitreous membrane. Contains 98-99% water, salts, sugars, collagen, hyaluronan, and proteins. No blood vessels present, viscosity 2-4 times water
The ciliary body is a ring-shaped thickening of tissue in the eye. It contains ciliary muscle, vessels, and fibrous connective tissue. The inner layer is transparent and continuous with the retina. The outer layer is highly pigmented and continuous with the retinal pigment epithelium