20/04/2017 0 Comments
Eye Doctor Explains the ‘Blind Spot’
Canadians take their vision seriously - the eye sends back signals that let humans navigate through the world successfully. We know that visual health is important, and that regular visits to an optometrist, like the professionals at The Eyewear Place, can detect eye issues and diseases early on, as well as get you a new prescription for eyeglasses or contacts during an eye exam.
Because the eye is a fascinating as well as integral part of our lives, learning how our vision works, and a few of the fun “trompe-l'œil” - French for “deceive the eye” – or optical illusions with our eyes, is always an interesting pastime. One of these natural tricks is the “Blind Spot”. Each human eye has a blind spot, and the brain sometimes has to fill in what is there by looking at the surrounding area.
How it works, is that your eye has an inner lining which is made of a sheet of nerves called a retina that is responsible for your vision and what you see. Photoreceptors cells in the retina detect light and allow you to perceive vision. In the centre of your retina is a “hole” or space where the Optic Nerve enters the eye called the Optic Nerve Head where there are no photoreceptors, and as such, there is no light or vision detected at this spot in the retina.
This is your “Blind Spot”.
Most of the time we never notice. The other eye will see what’s happening in its partner’s blind spot, but if the blind spots overlap while looking at a certain object, or if the person is only looking through one eye, the brain just fills in the spot looking at the surrounding picture. The fun in learning comes from this dramatic experiments to demonstrate the blind spot.
To draw the blind spot tester on a piece of paper, make a small dot on the left side separated by about 6-8 inches from a small + on the right side. Close your right eye. Hold the image about 20 inches away. With your left eye, look at the +. Slowly bring the image (or move your head) closer while looking at the +. At a certain distance, the dot will disappear from sight - this is when the dot falls on the blind spot of your retina. Reverse the process. Close your left eye and look at the dot with your right eye. Move the image slowly closer to you and the + should disappear. Try the same with colored paper, and your mind will fill in the background color of the paper when the mark gets in your blind spot.
Every eye has a blind spot - your blind spot in your right eye is slightly on your right and your blind spot in your left eye is slightly on your left. If you want to learn more interesting eye tricks - call The Eyewear Place today to set up an appointment. Walk-ins and new patients are always welcome at all of our locations including Fort McMurray, and Lloydminster.