A person who reaches 40 years or is in mid forties often experience his near vision becomes blurred. He may especially feel this when he is reading a book, or sewing or working on a computer. This is basically a type of vision disorder known as presbyopia. It is a condition related to aging process and no one can escape from it. The name presbyopia is derived from Greek which means ‘old eye’. Presbyopia occurs as the lens losses its flexibility as it become thick with growing age.
The lack of flexibility affects the ability of eye to focus on close objects.While reading, presbyopics have to hold a book or a magazine at an arm’s length for reading purpose. When sewing or stitching they have to strain their eyes. This may cause headache and eye fatigue. These are the first symptoms of presbyopia. This refractory error cannot be cured but can be corrected by wearing eyeglasses or contact lenses.
What Is The Cause Of Presbyopia?
Presbyopia is age related eye disorder. People over the age of 40 usually are affected with this refractory error of the eye. Normally the light reflected from object enters into the cornea.Light then passes through the lens and on the retina. The cornea is a transparent dome shaped membrane in the front part of eye. Lens is also transparent.
When light enters the eye from an object both lens and cornea bend the light so that it can be properly focused on the retina for an image to be formed. Lens is slightly flexible and elastic and thus it helps to focus properly the light entering on the retina.
But as the person ages the lens become less flexible. The muscle fibers which surround the lens are also affected due to aging process. Due to slight rigidity, lens is unable to change its shape and the light reflected from the close-up objects cannot be focused on the retina. The image generated is out of focus.
Age is one of the major risk factors for presbyopia. Almost all get affected with presbyopia after the age of 40. People suffering from diabetes and cardiac diseases may suffer from this condition early in life. Premature presbyopia is also observed in patients taking anti depressants and diuretics.
Early Symptoms Of Presbyopia
Presbyopia develops gradually over a period of time. It mostly occurs after the age of 40. The first sign of presbyopia is that a person has to hold reading material such as a magazine, reading books, newspaper at an arm’s length. It helps proper focusing at this distance.
Patient finds it hard to read fine print from a normal reading distance, the vision appears blurred. Patient has to strain his eyes while reading from a normal distance. This may lead to headache after reading or doing some work from a close distance.
How Can Presbyopia Be Corrected?
Presbyopia cannot be cured but the abnormal vision can be corrected easily by several means. One of the simplest ways to correct presbyopia is wearing eyeglasses with a higher focusing power usually on the lower side of the lens. This makes it comfortable for a person to read from the lower portion of the lens and see longer distance easily from the upper part of the eye glasses. Eyeglasses can be of three types, progressive, bifocals and trifocals.
The other option is to use contact lenses instead of eyeglasses for improving vision caused due to presbyopia. There are several types of lens such as bifocal lens and mono-vision lens.
Laser eye surgery is also helpful for correcting presbyopia.