Surface anatomy of the eye Over the iris the transparent layer is the cornea Pupil Sclera Iris Conjunctiva

Different color of iris in human eye Green in Asia Amber in Asia Blue eyes in Europe Albino In Europe Brown eyes in Asia, Africa, and Scandinavia Grayish eyes in Russia, Finland, North Africa

IRIS PLANT Iris is a genus of 260 species of flowering plants. It takes its name from the Greek word for a rainbow, referring to the wide variety of flower colors found among the many species. Iris latifolia

About Tapetum Lucidum The tapetum lucidum is a layer of tissue in the eye of many vertebrates animals, that lies immediately behind or sometimes within the retina. It reflects visible light back through the retina, increasing the light available to the photoreceptors. This improves vision in low-light conditions. The tapetum lucidum contributes to the superior night vision of some animals. Many of these animals are nocturnal, especially carnivores that hunt their prey at night, while others are deep see animals.

Tapetum Lucidum 1. Tapetum lucidum reflect lights and when the eyes examined it appears as a metallic green, blue, orange gold, brown. 2. The tapetum in horse, ruminants, man and few others animals is fibrous and can not reflect light. 3. The tapetum lucidum which reflects light consists of 10 – 15 layers of flat, irregular, pentagonal cells. Tapetum Lucidum Tapetum Lens Retina Tapetum

Different eye shines due to tapatum White eye shine in walleye fish Yellowish-green eye shine in cat and dog Yellow eye shine in raccoons Red eye shine in opossum, rodents and birds.

Brightness of human and dog eye MZI Khan Human eye can not shine because the tapetum is fibrous. Yellowish-green eye shine in dog due to tapetum lucidum

CATS EYE Carnivores can see in night due to: (1) Wide vertical pupil which permits more amount of light to enter in to the eye. (2) Presence of metallic green tapetum in between retina and choroids.

Vision in night snakes "see" their prey in green night-heat vision

Color blindness Rod cell are responsible for photosensation Cones for the color

Vision of Shark Sharks do not possess the same variety of photorec- eptors as humans.  They have few retinal cones, and as a result, most have no color vision.  They have much larger rod receptors (which pick up light), so their vision is much less acute than ours.

Color Blindness Human eye vision (color vision okay)                                                   Human eye vision (color vision okay) Horse vision (color blindness for red and green)