(hyperopia)

Prevalence of farsightedness (hyperopia) of Myopia Lower. Myopia is usually around +1 to +4 diopters and rarely reaches 8 diopters or higher. Farsightedness occurs when either the eye is shorter than the curvature of the cornea, or the cornea is shorter than the length of the eye, as a result, the light entering the eye is focused behind the retina. In this case, distant objects appear blurred and close-up images become even more blurred. Young people who are cameras can use the focusing power of the eye lens to throw the image from behind the retina onto the retina and see clearly. However, in extreme hyperopia or older age, this ability decreases and patients need reading glasses or double-vision glasses. With age, the ability to focus the image on the retina decreases and gradually the dependence of camera eyes on glasses increases. and they need a higher number. Usually, in people with cameras, the actual eye score is higher than the glasses they use. To correct a camera, convex lenses are used, which are prescribed with a positive (+) sign. The eye looks bigger behind these glasses. Often myopia is completely cured with femtolytic surgery.

Myopia

More than 25% of people in the world have some degree of myopia (approximately 15 million Iranians). Myopia is the medical term for nearsightedness. The most important cause of myopia is its hereditary condition. Myopia usually starts from the beginning of the second decade of life and increases with the growth of the eye size during puberty and usually stops after the age of 18. So far, it has not been proven that reading in childhood, reading for a long time, reading at night, watching TV closely, or using inappropriate glasses cause myopia. If it is more than normal, myopia is created. As a result, the light entering the eye is not accurately focused on the retina and the clarity of the images is reduced. The term myopia means that you can see near objects more clearly than distant objects. Of course, close objects can be seen clearly at a distance corresponding to the eye score. For example, a person with two degrees of myopia can see objects clearly at a distance of 50 cm from the eye. People with less than three degrees of myopia have the privilege of seeing close objects clearly without glasses. Many nearsighted people do not wear glasses while reading. Myopic eye disease is often treated with femtolytic eye surgery.

Astigmatism

Many people along Myopia They have some degree of astigmatism or oval shape of the cornea. Astigmatism occurs when the cornea is more cross-sectional than a baseball. As a result, due to unequal refraction in different parts of the cornea, the images are not completely focused on the retina, and the images are blurred both near and far. Therefore, people with high degrees of astigmatism not only see distant objects blurry like nearsighted people, but also see close objects blurry. Astigmatism is classified as follows:

• Mild astigmatism: less than one diopter
• Moderate astigmatism: one to two diopters
• Severe astigmatism: two to three diopters
• Very severe astigmatism: more than three diopters

Astigmatism has different types and can exist alone, along with nearsightedness or farsightedness.

presbyopia

The definition of presbyopia in one sentence is as follows: the progressive decrease in the ability to see near objects with age. Signs and symptoms of presbyopia:

• Inability to read books, newspapers, mobile phones, etc. closely
• Headache or eye pain while doing things like writing or sewing

No definitive treatment has been found for this problem, and the only way to manage presbyopia is to use converging lens glasses to be used when you need to see closely, which are called reading glasses. After a while, each of the people suffering from presbyopia find themselves surrounded by a collection of different types of glasses and many times they have them with them when they need them.