why do we have a blind spot in our vision
Our eyes have a blind spot for a very good reason. On the back of our eye, the retina is the stuff that detects the light. All the information that the retina picks up is sent to the brain through the optic nerve. The only problem is that the optic nerve needs a way to get out of the eye. The place where it leaves is where we have our blind spot. Since we have 2 eyes that can move around, we don't notice the blind spot often. Here's an interesting way to see your blind spot. First, take a piece of paper and draw 2 small dots on it. Cover one of your eyes. Hold the paper so the dots are on the same level (parallel to the ground).
Stare at one dot and slowly move the paper towards and away from you. You will see that the other dot will disappear. That is the dot in on your blind spot and your other eye cannot see it. p. s. You may wonder why the nerves go into the eye and then need a hole to come back out as a bundle in the optic nerve. Why not just head straight back out, and bundle up behind the eye, with no hole? For that, theres no good reason. Its an accident of evolution, where things happened to go wrong and then couldnt get fixed in small evolutionary steps. Squids and octopuses happened to get it right, and have no blind spots.
Mike W. (published on 10/22/2007)
Blind spot, small portion of the visual field of each that corresponds to the position of the optic disk (also known as the head) within the. There are no photoreceptors (i. e. , or ) in the optic disk, and, therefore, there is no image detection in this area. The blind spot of the right eye is located to the right of the centre of vision and vice versa in the left eye. With both eyes open, the blind spots are not perceived because the visual fields of the two eyes overlap. Indeed, even with one eye closed, the blind spot can be difficult to detect subjectively because of the ability of the to Бfill inБ or ignore the missing portion of the image.
The optic disk can be seen in the back of the eye with an. It is located on the nasal side of the, is oval in shape, and is approximately 1. 5 mm (0. 06 inch) in diameter. It is also the entry point into the eye for major that serve the retina. The optic disk represents the beginning of the optic nerve (second ) and the point where from over one million retinal cells coalesce. Clinical evaluation of the optic nerve is critical in the and monitoring of and other optic neuropathies that may lead to vision loss.
- Views: 118
why do they dilate your eyes for eye exam
why do they dilate your eyes during an eye exam
why do they dilate your eyes at the eye doctor
why do optical illusions trick your eyes
why do we have a blind spot in each eye