Photoreception (Vision): Eye Structures and Functions

Photoreception (Vision)

A. Pupil: Allows light into the eye.
B. Aqueous humour: Supplies the cornea with essential nutrients.
C. Iris: Controls the size of the pupil, regulating the amount of light entering the eye.
D. Ciliary body: Provides support to the lens and aids in controlling pupil size, influencing accommodation (focusing).
E. Sclera: Protects the eye and helps maintain its spherical shape. The choroid, which is associated with the sclera, nourishes the retina.
F. Retina: Contains photoreceptor cells, specifically rods and cones, which detect light and relay sensory input as electrical signals to the optic nerve.
G. Fovea Centralis: A specialized region within the retina that contains a high concentration of cones, responsible for sharp, detailed central vision.
H. Optic disc (blind spot): The specific point where the optic nerve attaches to the retina. This area lacks both rods and cones, resulting in a physiological blind spot.
I. Optic nerve: Relays visual information received from the retina to the brain for processing and interpretation.

J. Vitreous humor: A clear gel that fills the space between the lens and the retina, helping to maintain the eye's shape.
K. Suspensory ligament: Fibers that connect the ciliary body to the lens, holding the lens in place.
L. Lens: A transparent, biconvex structure that, along with the cornea, helps to refract light to be focused on the retina.
M. Cornea: The transparent outer layer at the front of the eye that covers the iris, pupil, and anterior chamber. It refracts light due to its curvature.