Retina
Retina (pars optica)
Sensory (eye & ear)OrgansHeadLeft and right
View left in 3D View right in 3D
- What it is
- The thin light-sensitive neural layer lining the back of the eye from the optic disc to the scalloped ora serrata. It has ten layers, with rods and cones at the back and the ganglion cells whose axons form the optic nerve on the inner surface.
- Function
- Converts the focused image into nerve signals and begins processing them (contrast, colour, motion) before sending them to the brain.
- Size
- About 0.25 mm thick (0.1 mm at the fovea); ~120 million rods and 6 million cones; surface ~1100 mm2.
- Clinical note
- A retinal detachment (flashes, floaters, a curtain over the vision) is an emergency; diabetes and high blood pressure can be seen directly in the retinal vessels.