Describe in detail about Retina
The retina is a highly complex layer of nervous tissue. The photoreceptors are rods and cones for scotopic and photopic vision respectively. The retina is structured such that several rods are connected to a single bipolar cell and each cone is connected to an individual bipolar cell. Cones are connected to each other by horizontal cells. Upon ophthalmic examination, the fundus oculi (including the retina, its vessels and the optic disc) are visible. The macula, about 5-6 mm in diameter, contains the fovea, which is responsible for colour vision and has the highest visual acuity. The optic disc is also called a blind spot while the macula is referred to as the yellow spot. The ora serrata (the intersection between the retina and the pars plana) can be seen through indirect ophthalmoscopy. The red colour of the fundus is because of the transmission of light reflected from the posterior 136 sclera through the capillary bed of the choroid.