Illusions of sight
People with poor eyesight are always marked illusions of sight .They are also in people with normal vision, but if the illusions of normal vision are evidence of relaxation, the illusions of imperfect vision are evidence of tension. Some people with an anomaly of refraction have a few illusions, others have a lot of illusions, because the tension causing the refraction anomaly is not the same stress that is responsible for illusions.
Illusions of imperfect vision can be related to the color, size, position and shape of the objects in question. They can include the emergence of things that are not in fact, various other strange and interesting phenomena.
ILLUSIONS OF COLOR
When a person sees a black letter and claims to be gray, brown, blue or green, it means that he suffers from the illusion of color. This phenomenon is different from what is called color blindness. A person with color blindness can not distinguish between colors, usually blue and green, and his inability to this is permanent. A person suffering from the illusion of color sees false colors impermanently and sees them as heterogeneous. When he looks at the black letters on the checklist, they may appear to him gray at one time, while in another one they already have shades of yellow, blue or brown. Some people always see black letters in red. To others they seem red only at times. Although all the letters are the same color, some people can see big letters in black, and small ones are yellow or blue. Usually large letters are seen as darker than small ones, no matter what color they are. Often different colors appear in the same letter. Part of it can be seen as black, and the rest is gray or some other color. On white, there may appear patches of black or colored, and spots of white or colored-on black.
ILLUSIONS OF
SIZE Large letters may appear small or, conversely, small letters may seem large. One letter may appear to be of a normal size, while another letter of the same size and from the same distance may seem larger or smaller in size. The letter may appear to have a normal size at the near-point and at a distance, but having only half that size at an average distance. When a person is able to correctly judge the size of a letter from all distances, up to 20 feet, his vision is normal. If from different distances this size seems different to him, then he suffers with illusions of size. At large distances, judgment about size is always imperfect, since at such distances vision is imperfect, although it is fine at ordinary distances. The stars seem to be points because the eye for objects at such distances has imperfect vision. A candle viewed from a half mile appears to be smaller in size than at a near point, but if it is viewed in a telescope that gives perfect vision at this distance, it will appear the same as at the near point. With improved vision, the ability to judge the size of objects is improving.
Correction of anomalies of refraction with spectacles rarely gives a person the opportunity to judge the size as correctly as a normal eye does. The ability to do this can vary significantly among people who have the same degree of refraction anomaly. One person with 10 eyeglasses dioptres corrected by glasses may be able( which is very rare) to correctly judge the size of objects. Another person, with the same degree of myopia and the same glasses, can see these things, which seem to have only half or a third of their usual size. This shows that the refraction anomalies have little in common with the wrong perception of size.
ILLUSIONS OF
FORM The round letters can appear square or triangular, straight letters can appear curved, letters of the correct form can appear having in the center a grid or a cross. In short, one can observe an indefinite number of changing forms. The main factors of this kind of imperfect vision are lighting, distance and the surrounding situation. Many people can see the shape of a letter correctly when other letters are covered with something, but are unable to do so if they are visible. Some people are helped by marking the position of the letters with the help of some pointer. Another pointer is so hampered that with it they can not see the letter as well as without it.
ILLUSIONS OF NUMBER
People with poor eyesight often see with both eyes together, with each eye individually or with just one eye multiple images. The manner in which these multiple images are manifested is sometimes very curious. For example, one patient with presbyopia normally read the word HAS with both eyes. He correctly read the left eye with the word PHONES, but when he read it with his right eye, he saw the letter "P" double, while the imaginary image was slightly to the left of the real one. The left eye, despite the fact that he had normal vision for the word PHONES, multiplied the axis of the pin when it was in an upright position. The head remained single and multiplied only when the position of the pin was changed to horizontal. But then the axis became single. When the tip of the pin was placed below some very small letter, the point sometimes doubled, despite the fact that the letter remained single.
No abnormality of refraction can explain such a phenomenon. These are the mistakes of the brain alone. The positions in which the multiple images are arranged are infinite. Sometimes they are located vertically, sometimes horizontally or obliquely, and sometimes in a circle, a triangle or in the form of other geometric figures. Their number can also vary from two to three, four or more. They can be motionless or more or less rapidly changing their position. They also differ in a certain degree of diversity in terms of color, including white( whiter than even the background color).
ILLUSIONS OF POSITION
The point following the letter on the same horizontal line as the bottom of the letter may seem to have changed its position in a wide variety of curious ways. The distance between it and the letter can change. It can be on the other side of the letter, above or below the line. Some people see letters in the wrong order. In the case of the word AND, for example, the letter "D" may take the place of the letter "N" or the first letter may change places with the last one.
All these phenomena are mental illusions. The letters sometimes seem more remote than they really are. Small letters from a distance of 20 feet may seem viewed from a distance of a mile. People suffering from distance illusions ask if the position of the checklist has been changed.
ILLUSIONS RELATED TO NON-EXISTING OBJECTS
When the eye has poor eyesight, the brain not only distorts what the eye sees, but also imagines that it sees things that do not really exist. Among illusions of this kind, there are floating particles that often appear before the eyes, when sight is imperfect and even when it is usually very good. These particles in science are known as muscae volitantes, or the symptom of "flying flies".Although their presence does not have any real significance, being merely a symptom of mental stress, they attract attention so much and usually excite people so much.
ILLUSIONS RELATED TO ADDITIONAL COLORS
When sight is imperfect, a person often after looking away from a black, white or some other brightly colored object and closing his eyes for a few seconds seems to be seeing this object, painted in an additional orclose to an additional color. If it is a black object on a white background, a white object on a black background will be seen. If the object is red, then it can be seen blue, and if it is blue, then the object can appear as red. These illusions, known as consecutive images, can also be seen, although less often, and with open eyes against any background that a person will have to look at. They are often so bright that they seem real.
ILLUSIONS RELATED TO THE SUN FLOWER
People with normal vision see the sun as white, whitest of the existing white. But when sight is imperfect, it can seem to have almost any color of the spectrum-red, green, purple, yellow, etc. It is known that quite often the sun was described by people with visual impairment completely black. The setting sun usually seems red due to atmospheric conditions. But in many cases, these conditions are not enough to change the color, and still people with poor eyesight seem red, and people with normal vision - white. If the redness of the red sun is an illusion, and not a consequence of atmospheric conditions, the image of the sun on the frosted glass of the camera will be white, not red. The rays focused by the magnifying glass will also be white. The same is true for the red moon.
THE BLIND STAINS AFTER THE SUN
After looking at the sun most people see black or colored specks that can last from a few minutes to a year or more, but never remain forever. These spots are also illusions, and not the consequence, as it is usually asserted, of any organic change in the eyes. Even complete blindness, which sometimes appears temporarily after looking at the sun, is just a false impression of the eye about sensory perception.
ILLUSIONS RELATED TO THE FROST OF THE STARS
The fact that the stars twinkle is reflected in both the songs and the stories. It is usually believed that this phenomenon is in the order of things. However, it can be proved that the alleged flicker is just a psychic illusion.
THE REASON OF ILLUSIONS OF THE UNBOLLED VISION
All illusions of imperfect vision are the result of mental stress. When, for any reason, there is a disturbance of mental balance, there is a possibility of various kinds of illusions. This stress is not only different from the tension creating the refraction anomaly, but what can be proved, for each kind of these illusions there is a kind of voltage. The change in color does not necessarily lead to a change in the size or shape of objects or the appearance of any other illusions. You can clearly see the color of the letter or part of the letter without recognizing the letter itself. To black letters turned to blue, yellow or letters of other colors, you need a subliminal effort to remember or imagine the right colors, while to change the shape, you need a subliminal effort to see the shape in question. With little practice, any person can learn to create illusions of form and color, deliberately straining in the same way that he strained unconsciously. Whichever illusions are made in this way, it will be found that there will also appear an eccentric fixation and one of the refractive anomalies.
The stress that leads to polyopia, again, differs from the tension creating illusions of color, size and shape. After several attempts, most people manage to easily produce the Noliopia at will. A close look or mowing of the eyes, if the voltage is large enough, usually lead to a person starting to see double images. Looking over the light source or letter and trying to see them as well as when looking directly at them, you can create the illusion of several light sources or letters located vertically. If the voltage is large enough, there may be a dozen of them. Looking sideways from a light source or letter or looking away from them at some angle, these images can be aligned horizontally or obliquely at any angle.
To see objects in the wrong location( for example, to place the first letter of a word in the last place), one must use the skill of eccentric fixation and learn a mental representation that differs from the usual one.
Black or colored spots that are visible after looking at the sun, and strange colors, which sometimes seem painted the sun, are also the result of mental stress. When a person learns to look at the sun without stress, these phenomena will immediately disappear.
Sequential images were attributed to fatigue of the retina, which is supposedly so over-stimulated by some color that it can no longer perceive it and thus seeks relief in a shade complementary to the given color. If, for example, she is tired of looking at the black beech "C" on the checklist, it is assumed that relief will be found in the vision "C" white. This explanation of the phenomenon is very clever, but hardly corresponds to the truth. Eyes can not see when they are closed. If a person in this case seems to be seeing something, it means that he has undergone a psychic illusion, to which the retina has nothing to do. The eyes can not see what is not in reality. If a person thinks that he sees the white letter "C" on a green wall where there is nothing like it, then again it is obvious that he succumbed to a mental illusion. The sequential image, in fact, testifies simply to the loss of mental control and occurs along with one of the refractive anomalies, since this condition is also associated with the loss of mental control. Any person can create sequential images at will, trying to see the big letter "C" all equally well, that is, under tension. At the same time, it can be viewed indefinitely by the way of central fixation without such consequences.
Although people with visual impairments usually see stars shimmering, they do not necessarily have to see them like that. Consequently, it is obvious that the voltage that causes flicker differs from the voltage leading to the refraction anomaly. If a person looks at the star without making any effort to make an effort to see it, it will not flicker. If the illusion of flickering begins, it can usually be stopped, "shaking" the star. On the other hand, you can make the planets flicker, or even the moon, if a person strains enough to see them.
ILLUSIONS OF NORMAL VISION
Illusions of normal vision include the phenomenon of central fixation. When the eye with normal eyes looks at the letter on the check table, it sees the fixed point better than all the others. Any other object in the field of view at the same time seems less clear. In reality, the whole letter and all letters can be completely black and crisp, and the impression that one letter is blacker than others, or that one part of a letter is blacker than the remainder is an illusion. However, the normal eye is able to move with such rapidity that it seems that the entire line of small letters is visible the same at the same time. Of course, in fact, there is no such image on the retina. Each letter is seen separately. When the letters are viewed from a distance of 15-20 feet, they can not be identified unless about four movements are made for each letter. Therefore, in order to create the impression of a simultaneous vision of 14 letters, about 60-70 images should be created on the retina, each with one point, more distinct than the others. Now, apparently, it is clear that the idea that letters are seen as identical all at once is nothing more than an illusion.
Here we come across two different kinds of illusions. In the first case, the impression perceived by the brain corresponds to the image on the retina, but it does not correspond to reality. In the second case, mental perception is in accordance with reality, but does not correspond to the image on the retina.
A normal eye usually sees the background of a letter whiter than it actually is. When looking at the letters from the test table, he sees white stripes at the edges of the letters. When reading a small font, the normal eye sees the white space between the lines and letters and the white space of the open letter spaces more intense in color than it really is. People who can not read the fine print can also observe this illusion, but less clearly. The clearer this illusion is, the better the vision. If it can be imagined consciously( with normal vision it appears unconsciously), then vision improves. If the lines of small print are covered by something, then the stripes between them disappear. When the eye with normal vision looks at the letters through the magnifying glass, this illusion does not disappear, but the intensity of white and black color drops. With poor vision, their intensity can be strengthened in a similar way to some extent, but still it will be weaker than in the case of normal eyes.
The illusions of movement caused by the movement of the eye should also be considered illusions of normal vision. The same should be said about the perception of objects in the right position. The latter is the most curious illusion of all. Regardless of the position of the head and despite the fact that the image on the retina is turned upside down, we always see things in the right position.