We also see how the retina (yellow surface) covers the entire posterior wall except for the passage of the blood vessels, which is our blind spot. Within the posterior cavity, we see a small indentation known as the fovea. The eye can be divided into anterior and posterior cavities. This is because the fovea is where the least amount of incoming light is absorbed by other retinal structures, shown in f igure 1 below.įigure 1: Structure of the Eye. Therefore, visual acuity, or the sharpness of vision, is greatest at the fovea. Therefore, the fovea is where the least amount of incoming light is absorbed by other retinal structures, as see in f igure 1 below. However, in the centre of the retina, called the fovea, there are only cones cells with very few structures absorbing light in front of them. A significant amount of light is absorbed by these structures before the light reaches the photoreceptors. Note that the photoreceptors (cones and rods) in the retina are located behind the axons, RGCs, bipolar cells, and retinal blood vessels, shown in f igure 2b below.

This creates a “blind spot” in the retina, and a corresponding blind spot in our visual field. Because these axons pass through the retina, there are no photoreceptors at the very back of the eye, where the optic nerve begins. The axons of RGCs, which lie at the innermost layer of the retina, collect at the optic disc and leave the eye as the optic nerve, as see in f igure 3. There, amacrine cells additionally contribute to retinal processing before an action potential is produced by the RGC. It is the bipolar cell in the retina that connects a photoreceptor to a retinal ganglion cell (RGC) in the inner synaptic layer. The change in membrane potential alters the amount of neurotransmitter that the photoreceptor cells release onto bipolar cells in the outer synaptic layer. The photoreceptors (rods and cones) change their membrane potential when stimulated by light energy. The retina is composed of several layers and contains specialized cells for the initial processing of visual stimuli. The posterior cavity is filled with a more viscous fluid called the vitreous humor. The posterior cavity is the space behind the lens that extends to the posterior side of the interior eyeball, where the retina is located.

It is filled with a watery fluid called the aqueous humor. The anterior cavity is the space between the cornea and lens, including the iris and ciliary body. The eye is also divided into two cavities: the anterior cavity and the posterior cavity. The innermost layer of the eye is the neural tunic, or retina, which contains the nervous tissue responsible for photoreception. To appreciate the brain’s role in visual processing.

Descriptions of the function of photoreceptors in the transduction of light.

To identify anatomical structures of the eye.

Visual cues physiology