Eye and Vision Anatomy

P-cells or midget cells have a slow conduction velocity and respond to a change in colour. They respond only weakly to changes in contrast, unless the change is great.

The lateral geniculate nucleus (LGN) is a relay center in the thalamus for the visual pathway. It receives a major sensory input from the retina.

Optokinetic reflex allows the eye to follow objects in motion even when the head remains stationary.

Lacrimal artery is the largest branch of the opthalmic artery which supplies blood to the lateral rectus muscle of eye. It accompanies the lacrimal nerve along the upper border of the lateral rectus and supplies the lacrimal gland.

The lateral rectus muscle is responsible for lateral movement of the eyeball, specifically abduction.

The palisades of Vogt are distinctive normal features of the human corneoscleral limbus. The functions of the palisades of Vogt are not known with certainty, but their interpalisadal epithelial rete ridges may serve as a repository for corneal epithelial cells.

Vascular tunic layer of the eye consists of choroid, ciliary body and iris.

Hyaloid canal contains lymph. Its purpose is to facilitate changes in the volume of the lens. As the lens expands in positive accommodation, its volume increases. It results in the compression of the hyaloid canal so that the volume of the eye remains constant.

Zonule of Zinn is a suspensory ligament of the lens. It is a ring of fibrous strands connecting the ciliary body with the crystalline lens of the eye.

Sphenoid bone is the origin of the levator palpebrae superioris muscle of eye.

Lateral rectus muscle of the eye is innervated by the abducens nerve. It controls the movement of the lateral rectus muscle.

Fovea is present in the centre of the macula of retina. It is responsible for sharp central vision although it is less sensitive to light as it lacks rods.

Inner plexiform layer of the retina is formed by interlaced dendrites of retinal ganglion cells. It also contains cells of inner nuclear layer.

Giant retinal ganglion cells contain a photo-pigment (melanopsin) allowing them to respond directly to light.

Uvea is the richest in immune system. It consists of many immune cells including macrophages, dendritic cells and mast cells.