In contrast, in the cephalopod retina, the photoreceptors are in front, with processing neurons and capillaries behind them. No photoreceptors are in this region, giving rise to the blind spot. The ganglion cells, whose axons form the optic nerve, are at the front of the retina therefore, the optic nerve must cross through the retina en route to the brain. The vertebrate retina is inverted in the sense that the light-sensing cells are in the back of the retina, so that light has to pass through layers of neurons and capillaries before it reaches the photosensitive sections of the rods and cones. Structure Inverted versus non-inverted retina The retina is the part of the body with the greatest continuous energy demand. Like most of the brain, the retina is isolated from the vascular system by the blood–brain barrier. It is the only part of the CNS that can be visualized noninvasively. In vertebrate embryonic development, the retina and the optic nerve originate as outgrowths of the developing brain, specifically the embryonic diencephalon thus, the retina is considered part of the central nervous system (CNS) and is actually brain tissue. Neural signals from the rods and cones undergo processing by other neurons, whose output takes the form of action potentials in retinal ganglion cells whose axons form the optic nerve. Light striking the retina initiates a cascade of chemical and electrical events that ultimately trigger nerve impulses that are sent to various visual centres of the brain through the fibres of the optic nerve. A third type of light-sensing cell, the photosensitive ganglion cell, is important for entrainment of circadian rhythms and reflexive responses such as the pupillary light reflex. Cones function in well-lit conditions and are responsible for the perception of colour through the use of a range of opsins, as well as high-acuity vision used for tasks such as reading. Rods function mainly in dim light and provide monochromatic vision. The primary light-sensing cells in the retina are the photoreceptor cells, which are of two types: rods and cones.
The neural retina consists of several layers of neurons interconnected by synapses and is supported by an outer layer of pigmented epithelial cells. The retina serves a function which is in many ways analogous to that of the film or image sensor in a camera. The optics of the eye create a focused two-dimensional image of the visual world on the retina, which then processes that image within the retina and sends nerve impulses along the optic nerve to the visual cortex to create visual perception. Very pleased and thank you for making me feel good about being cared for here." - Shayla M.The retina (from Latin: rete "net" PL: retinae or retinas) is the innermost, light-sensitive layer of tissue of the eye of most vertebrates and some molluscs. It’s important to have that feeling that you are in good hands these days and he most definitely did that including the staff I interacted with. Chiang made me feel very confident & appreciate the time he took with me and didn’t make me feel like just a number. I really wanted to cry tears of joy for finally being listened to, taken seriously, and getting answers. No one could give me answers until I came here. I had been anxious for two years about what was happening. Spirn confirmed he could also see the floaters and settled my nerves. Spirn and his staff truly listened to what I had to say and fully tested my vision and eyes. Maybe it’s just ocular migraines and you're imagining the floaters from the migraines." I have seen the same floaters every day, and I was beginning to think maybe I’m just crazy and seeing things that aren’t there. I don’t see what you are talking about” or “your eyes look fine.
I have been to two other eye doctors who all said the same thing - “I don’t see anything.
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