Cow eye – Dissection and LabelBy Leslie Young

Section 63

Cow eye shown with labeled cornea.

The cornea is the transparent front part of the eye that covers the iris, pupil, and anterior chamber. The cornea, with the anterior chamber and lens, refracts light, with the cornea accounting for approximately two-thirds of the eye's total optical power.

Cow eye-shown with labeled Sclera

The sclera (from the Greek skleros, meaning hard[1]), also known as the white of the eye, is the opaque, fibrous, protective, outer layer of

the eye containing collagen and elastic fiber.

Cow eye-shown with lens dissected.

The crystalline lens is a transparent, biconvex structure in the eye that, along with the cornea, helps to refract light to be focused on the retina.

Cow eye-shown with dissected optic nerve

The optic nerve, also known as cranial nerve 2, transmits visual information from the retina to the brain.

Cow eye-shown with dissected iris.

The iris (plural: irides or irises) is a thin, circular structure in the eye, responsible for controlling the diameter and size of the pupil and thus the amount of light reaching the retina.

Cow eye-shown with dissected ora serrata

The ora serrata is the serrated junction between the retina and the ciliary body. This junction marks the transition from the simple non-photosensitive area of the retina to the complex, multi-layered photosensitive region. In animals in which the region does not have a serrated appearance, it is called the ora ciliaris retinae.

Cow eye-shown with dissected pupil.

The pupil is a hole located in the center of the iris of the eye that allows light to enter the retina.[

Cow eye-shown with dissected tapetum lucidum

The tapetum lucidum (Latin: "bright tapestry", plural tapeta lucida)[1] is a layer of tissue in the eye of many vertebrate animals.[2] It lies immediately behind the retina. It reflects visible light back through the retina, increasing the light available to the photoreceptors, though blurring the initial image of the light on focus. 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 sea animals.

Cow eye-basic function of the eye in higher organisms.

Eyes are organs that detect light and convert it into electro-chemical impulses in neurons. The simplest photoreceptor cells in conscious vision connect light to movement. In higher organisms the eye is a complex optical system which collects light from the surrounding environment, regulates its intensity through a diaphragm, focuses it through an adjustable assembly of lenses to form an image, converts this image into a set of electrical signals, and transmits these signals to the brain through complex neural pathways that connect the eye via the optic nerve to the visual cortex and other areas of the brain. Eyes with resolving power have come in ten fundamentally different forms, and 96% of animal species possess a complex optical system.