Visual coding

Light enters the eye through an opening in the center of the iris called the pupil.

Then, it is focused by the lens and cornea.

Light is projected onto the retina, the rear surface of the eye, which is lined with visual receptors

The message goes from the back of the eye to bipolar cells, which then send their messages to ganglion cells. These are located in center of the eye.

As a result of the anatomy of the eye, there is a blind spot at the optic nerve, which has no photoreceptors.

A tiny area specialized for acute, detailed vision as a result of the number of cones (which are perceptive to bright light)

While the periphery of the eye is more sensitive to faint light as it consists of more rods.

Rods: found in periphery, responds to faint light well

Cones: found in fovea, responds to bright light well

Ex. looking at night sky, sometimes you can see a faint star in your periphery but not by directly looking at it

Photopigments are chemicals that release energy when struck by light (derivitive of Vitamin A)

Opsins modify these photopigments so that they react to diff wavelengths of light)

The energy released then activates second messenger in the cell

There are three main types of cones; red, blue, green.
Blindness caused by deficincy in one of these (the red/green one), occurs more in males bc only have one X chromosome