Optic chiasma-Where the optic nerves converge laterally to connect to each other medially
Optic tract-The route of the ganglionic axons
Visual cortex-Part of the brain in the optical lobe which receives projections from ganglionic axons
Visual field-The image seen by each eye (also known as depth perception)
How We See?
Focusing- Light rays that enter the eye must come to the retina. The cornea and lens bend the rays toward one another and travel to the vitreous humor and strike the retina.
Depth Perception- The lens system is like a camera and reverses images. Optic nerves from the two eyes meet at the base of the brain at a point called the opticchiasma. The brain then processes the image.
Test for colorblindness online: http://www.toledo-bend.com/colorblind/Ishihara.html
Disorders of the eye’s outer parts
Sty- An eye lash follicle becomes inflamed. A sty looks like a pimple on the edge of the eyelid. Sties may be treated by applying a moist, warm cloth to the area and by using antibiotics prescribed by a physician. In some cases, pus from a sty may have to be drained by minor surgery.
Conjuctivitis- Conjuctivitis is an inflammation of the conjunctiva. This is commonly called pinkeye. This is often contagious and treated with eye drops.
Nearsightedness and Farsightedness
Nearsightedness occurs if light rays from distant objects meet before they reach the retina.
Farsightedness occurs if light rays from distant objects reach the retina before they meet.
If you're nearsighted, your prescription is a negative number