What is the retina of the eye and what is its function?
1 Answer
The organ of vision is the retina of the eye. The sensory receptors are called photoreceptors. When photoreceptors are stimulated, impulses travel within the optic nerve (CN II) to the visual (occipital) cortex for interpretation.
A picture of the retina can be taken with a camera attached to an ophthalmoscope. The optic disc is the very light spot here.
The optic disc is the location on the retina where nerve fibers leave the eye and join with the optic nerve; the central artery & vein also pass through this disk.
No photoreceptors are present in the area of the optic disk = blind spot.
There are two types of visual receptors (photoreceptors) in the retina:
Cones = photoreceptors for color vision; produce sharp images.
Rods = photoreceptors for night vision; produce silhouettes of images
Macula lutea –yellow spot of mostly cones
Fovea centralis – depression of ALL cones, sharpest vision
