The Human Eye

3 Tunics of the Eye 1. Fibrous tunic – outer protection and support. a) cornea • anterior 1/3 of eye • non-elastic (it has the same constant refractory index) • consists of high amounts of collagen fibers • only organ transplanted from one individual to another without rejection • for light refraction (light bending),(most important. feature regarding refraction) • cornea and lens are involved with refraction o the lens is not part of any tunic, because of the variable elastic change (it is elastic) …showed first 75 words of 672 total…

…showed last 75 words of 672 total…myopia – nearsighted, image converges in front of retina instead of striking the retina, problem is fixed using a concave lens 3. hyperopia – farsightedness, image converges behind retina instead of striking retina, problem is fixed using a convex lens Chapter 17 Endocrine System • [endo glands release hormones (chemical messengers) into the bloodstream  affect on some metabolic activity in body] example is the pancreas (endocrine organ) increase in blood glucose level (stimulus) causes the release of the hormone insulin.