|What is an optical illusion?|
An optical illusion is a misconception of what appears to a patients eyes but is not actually present. In other words, something a patient perceives but is not actually there. An optical illusion can be reproduces, that is, different observers see the same thing.
Another kind of optical illusion is due to the flaws and imperfection of the human eye namely the rods and retina. What the brain sees differs from what the eye is seeing. An example is the effect of a bleached retina : stare at a source of light for a period of time, after that look at objects around you. You will notice that there will be a black area (formed by the bleached retina) in your vision. When you close your eyes, the same area turns luminous.
|How does an optical illusion occur?|
Optical illusion occurs due to flaws in optical system. Twinkling of stars, of example, is caused by imperfections of eyes due to the long distance from the star. Because of the way the eye processes the information and delivers the information by electrical impulses to the brain; there are 120 000 000 rods, 6 000 000 cones and only 1 000 000 optical nerve fibres. Thus there is an evident compression ratio of 1:126 Thus the brain can be tricked under certain circumstances. Sometimes, the brain is tricked due to experience.
|Does it affect our daily lives?|
Yes, but only on a minor scale. A mirage seen in a desert is also due to optical illusion. Optical illusion can be also used in architecture and design. Optical illusion changes the perspectives, for example, plump people who wear vertical stripes tend to look thinner, the vice versa is also true for slender people who wear horizontal stripes.
|What are some examples of optical illusions in our daily lives?|
Architects use optical illusion in buildings to create the illusion of depth and space. Magicians use it in tricks for our amusement.
|Are any groups of people of people more susceptible to optical illusions?|
No, optical illusion occurs to everyone with the ability to see. Therefore, everyone with the ability to see will have optical illusions occuring!
|Is optical illusion heritable?|
Optical illusion is not heritable; if you have a brain, you will have optical illusion as it is consistent with everybody, except those who are colour blind. People with colour blindness tend to see optical illusion differently who those who have normal vision, their after image will be those of a complimentary colour, example, orange after image will be seen as blue.
It is interesting to note that during WWII, colour blind people were used to spot armies in camouflage as they had different perceptions and could easily spot the soldiers.
|Will optical illusion worsen with age?|
No, optical illusions will not worsen with age, however it can be affected by cataracts.
|Can the effects of optical illusion be prevented or lessened? Can it be treated?|
No, Optical illusion can not be prevented because of an optical illusion to occur, one must be able to see, therefore, as long as you can see, you will have optical illusions. Aslo, an optical illusion cannot be treated!