What is a blind spot and why it is necessary
To begin with – a simple test that will prove that vision in some moments will surely fails you. Take a look at the picture below. Left – Fat Cross. On the right – the same cross, but prisonered in a circle. Both objects are distinguishable and obvious, though?
And now complete a few simple actions.
- Blank right eye with palm.
- Look at the right eye, look at the right cross – the one that arms the circle. Note for yourself that lately vision you continue to see the left cross.
- Do not take a look from the right cross, start slowly bringing the face to the monitor or remove from it. At a certain point, you will notice that the left crossed disappeared.
- Stopping. Secure this moment. Right cross, from which you do not look around, on the spot. And there is no left. Although in fact he is.
So manifests itself physiological phenomenon called blind spot that hides a piece of reality from us.
What is a blind spot
The blind spot is called the Blind Spot area on the retina eye, immune to the light. There are simply no photo seventors in it – the most famous biology of chopsticks and colodes, which convert light irritation in the nerve impulses transmitted to the brain.
And since there are no photoreceptors, it means that we are not able to see the object, the light from which falls into the blind zone. Even if it is located right under our nose.
Why do we need a blind spot
This kind of fee for the opportunity to see, due to the structure of the Structure and Function of the Eyes eye.
Illustration: Caerbannog / Wikimedia Commons
The inner shell of the eye (retina), millions of photoreceptors. Nerve fibers of the photosensitive cells which transmit signals over the stretch retina.
In a certain area of the fundus they get together and form the optic or visual, nerve, which is directly related to brain. The nerve passes through the retina, as if it severs. In place of a blind spot formed gap.
Why we do not notice a blind spot in ordinary life
Because we have binocular (from Lat. Bini – "Two" and Oculus – "Eye") Vision. Each of the two eyes has its own blind spot. They do not coincide, so the point "blindness" of the right eye effectively overlaps the left and vice versa.
In addition, the brain introduces its contribution: it complements the missing information about the image of the picture, which, in his opinion, should be there.
What to do if obvious blind spots appear before your eyes
But this is a bad bell. Normal, healthy blind spot we noticate not in a state – according to the reasons described above. The only way is to close one eye so that it can not compensate for the blind zone of the second. But even in this case, the blind spot will be very small, and to catch it, you will have to make some efforts. For example, as in the illusion that this article began.
But if you look at the world with both eyes and at the same time note the invisible zones – as a rule, they have a muddy gray color – or when viewed with one eye, the blind spot has become more and more noticeable, it is necessary to visit the oculist as soon as possible. It may be symptoms of Blind Spot in Eye serious violations.