Surface anatomy of the eye

ScleraIris

Pupil

Over the iris the transparent layer is the cornea

Conjunctiva

Different color of iris in human eye

Blue eyes in Europe Green in Asia Amber in Asia

Brown eyes in Asia, Africa, and Scandinavia

Grayish eyes in Russia, Finland, North Africa

AlbinoIn Europe

IRIS PLANT

Iris is a genus of 260 species of flowering plants.It takes its name from theGreek word for a rainbow,referring to the widevariety of flower colorsfound 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

TapetumLucidum

RetinaTapetum

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.

Lens

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 eyeMZI Khan

Yellowish-green eye shine in dog due to tapetum lucidum

Human eye can not shine because thetapetum is fibrous.

CATS EYE

Carnivores can see in night due to:(1) Wide vertical pupil which permits more amount oflight to enter in to the eye.(2) Presence of metallic greentapetum 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 thanours.

Color Blindness

                                                 

Human eye vision (color vision okay)

Horse vision (color blindness for red and green)