NERVOUS SYSTEM SENSES - VISION

Vision

The ability to see, which involves the eye perceiving light and processing visual information.

Refraction

The bending of light as it passes through materials of different densities.

Conjunctiva

A thin, transparent membrane lining the eyelids and covering the eye's surface; secretes mucous to prevent drying.

Lacrimal Gland

Produces tears for cleansing the eye, located lateral and superior to each eye.

Rods

Photoreceptors in the retina responsible for gray-scale vision in low light.

Cones

Photoreceptors responsible for color vision, requiring more light to function.

Sclera

The tough, fibrous outermost part of the eye that is white and protects the inner structures.

Iris

The colored part of the eye that regulates the size of the pupil.

Macula Lutea

A yellowish spot on the retina that contains a high concentration of cones.

Fovea Centralis

The center of the macula; an area with only cones, providing the sharpest vision.

Glaucoma

A condition caused by excess aqueous humor leading to pressure buildup, damaging retinal neurons.

Astigmatism

A vision condition caused by an irregular curvature of the cornea or lens, leading to blurred vision.

Myopia

Nearsightedness, where the image focuses in front of the retina.

Hyperopia

Farsightedness, where the image focuses behind the retina.

Binocular Vision

Vision that uses both eyes to provide depth perception.

Optic Nerve

Cranial nerve II that carries visual information from the retina to the brain.

Color Blindness

A genetic disorder affecting the cones, primarily in males, due to X-linked inheritance.

Ciliary Body

Smooth muscle structure around the lens that produces aqueous humor.

Aqueous Humor

Fluid produced by the ciliary body that maintains intraocular pressure and nourishes the eye.