7/18/2019 The Eye - Anatomy 1

http://slidepdf.com/reader/full/the-eye-anatomy-1 1/5

Iris controls how much light enters the

Cornea transparent so light can pass throu

Lens light enters here and image is focuonto the retina

Retina

transduction of light into neuronal signal, mostphotoreceptors, image is inverted, light passes thr

ganglion cells and bipolar cells and hits photorecep

Optic Nerve Carries signal to the brain

7/18/2019 The Eye - Anatomy 1

http://slidepdf.com/reader/full/the-eye-anatomy-1 2/5

Fovea Region of highest aquity, colour vision due to hiconcentration of cones

Types of Photoreceptors Rods and Cone

RodsMore sensitive to light, monochromatic: colour not d

located mostly outside of the fovea

Cones

Less sensitive to light, trichromatic; sensitive to blueor red, located in fovea responsible for high visual a

Blind Spot at the Optic Discarea on the retina where the optic nerve fibers exitretina, where there are no photoreceptors therefor

 vision

7/18/2019 The Eye - Anatomy 1

http://slidepdf.com/reader/full/the-eye-anatomy-1 3/5

Phototransduction Turning light into neural signals

Stage 1 Photopigments in photoreceptoractivated by light

Stage 2 Photoreceptor hyperpolarized

Stage 3

hyperpolarization decreases release of inhibitory NT to depolarization caused by disinhibition

Disinhibition removal of inhibitory influence

7/18/2019 The Eye - Anatomy 1

http://slidepdf.com/reader/full/the-eye-anatomy-1 4/5

Stage 4 Depolarization of bipolar cells may lead to an Apropagation along galgion cell

Causes of blindness1. Cataract 2. Glaucoma 3. Macul

Degeneration

Cause of Cataract clouded lens

Symptoms of a Cataract

 blurred vision

Cause of Glaucoma Intraocular pressure

7/18/2019 The Eye - Anatomy 1

http://slidepdf.com/reader/full/the-eye-anatomy-1 5/5

Symptoms of Glaucomaperipheral vision decreases leading

tunnel vision

Cause of Macular Degeneration fatty tissue deposits under RETIN

Symptoms of Macular Degeneration affects foveal vision