Human have three receptors, called cones, in our eyes that allow us to see the world in color. They sense three wavelenghts of light the best: blue light, green light, and red light. Just like in primary school where we learn that when we mix white and red we get pink paint, our brains use the mixture of signals that are received from those cones to make the colors that we see every day. The reason why we cannot see ultra violet light or infrared light is because we do not have the cones that would allow us to do so.
Transient monocular vision loss, or short-term vision loss in one eye, is becoming more and more common. But what’s causing this? It’s not blood clots or trauma; it’s our smartphones.
There are unique cells in the retina called melanopsin retinal ganglion cells. These cells do not assist in the formation of images in our brains. Instead, they send messages to a brain region called the suprachiasmatic nucleus that is located in the hypothalamus, concerning the brightness of the world around us. These signals provide information that contributes to our circadian rhythm. The circadian rhythm is our internal clock that tells the body when it is time to sleep and wake up.
Wouldn’t it be cool to be able to regrow a limb if you lost it? What about if you could regain vision if you lost the structure or “limb” in the eye that is responsible for your sense of sight? In recent research done by the National Eye Institute of the National Institute of Health, Müller cells were discovered to grow into interneurons, brain cells that transmit information to other brain cells, when the eye experienced injury from trauma or disease.