The Eye Human eye is an elongated sphere 2.5 cm in diameter with three layers.
{"Image DocumentName": "The EyeHuman eye is an elongated sphere 2.5 cm in diameter with three layers.", "Image ImageDescription": "Sclera is outer, white fibrous layer that covers most of eye; it protects and supports eyeball. Cornea is a transparent part of sclera at front of the eye that is window of the eye. Middle, thin, dark-brown layer is choroid containing many blood vessels and pigments absorbing stray light rays. To front of eye, choroid thickens and forms ring-shaped ciliary body and finally becomes the iris that regulates size of the opening called a pupil. Lens divides eye cavity into two portions: aqueous humor fills anterior cavity and vitreous humor fills posterior. Inner layer, retina, contains photoreceptors: Rod cells: about 125 million; contain rhodopsin, a pigment sensitive at low light levels (Vit A) Cone cells: about 7 million; stimulated by bright light (sharp images and colors) Fovea centralis is a small area of retina that contain only cones; this area produces acute color vision in daylight. Cone cells are barely sensitive at low intensity at night; at this time, the rods are still active.", "Image XResolution": "37", "Image YResolution": "37", "Image ResolutionUnit": "Pixels/Centimeter", "Image Software": "SlidePlayer", "Image YCbCrPositioning": "Centered"}