HPU Special Senses- Eye

Photoreceptors

Cells in the retina that respond to light; specifically rods for night vision and cones for day vision.

Rods

Photoreceptor cells that are more sensitive to light and are primarily used for night vision.

Cones

Photoreceptor cells that are less sensitive to light than rods and are used for day vision and color perception.

Retina

The layer at the back of the eye containing photoreceptors; responsible for converting light into neural signals.

Optic Nerve (CN II)

The second cranial nerve that transmits visual information from the retina to the brain.

Oculomotor Nerve (CN III)

The third cranial nerve responsible for controlling most of the eye’s movements and raising the eyelid.

Mydriasis

The dilation of the pupil.

Miosis

The constriction of the pupil.

Depth Perception

The ability to perceive the distance of objects, made possible by the cooperative function of both eyes.

Glaucoma

A group of eye conditions that can lead to damage to the optic nerve, often associated with increased intraocular pressure.

Amblyopia

Also known as lazy eye, a vision development disorder where the eye fails to achieve normal visual acuity.

Age-Related Macular Degeneration (AMD)

A medical condition which may result in blurred or no vision in the center of the visual field.

RPE (Retinal Pigment Epithelium)

A layer of cells that nourishes the retinal visual cells and is crucial in the visual process.

Visual Cortex

The part of the brain that processes visual information.

Choroid

The layer of blood vessels and connective tissue between the retina and sclera, providing nourishment to the retina.

Sclera

The white outer coating of the eyeball, protecting the eye and providing structural support.

Pupil

The adjustable opening in the center of the eye that allows light to enter.

Lens

The transparent structure in the eye that focuses light onto the retina.

Intraocular Pressure (IOP)

The fluid pressure inside the eye, which is an important measure in diagnosing glaucoma.

Ophthalmic Nerve

The first division of the trigeminal nerve (CN V) responsible for sensation in the forehead, upper eyelids, and part of the nose.

Ciliary Body

The part of the eye that contains the ciliary muscle and controls the shape of the lens.

Extraocular Muscles

The muscles that control the movement of the eye.

Blepharitis

Inflammation of the eyelids, causing red, swollen, and scaly eyelids.