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Definition of presbyopia

All eyes naturally have a transparent convex lens located behind the iris and connected to the ciliary muscles through narrow fibers called the zonule. The lens of the human eye is like a photographic camera lens that makes the image clear by rotating and focusing and changes the convexity of the eye lens by contracting the ciliary muscles. This act of changing the convexity of the eye lens due to the contraction of the ciliary muscle is called accommodation. When the eyes look at objects at different distances, the lens of the eye, which has elasticity, focuses the image of objects on the retina by changing the convexity of the lens, and makes people see objects clearly at all distances. Over time and with increasing age, the elasticity of the lens of the eye and the strength of the ciliary muscle decrease, and the amount of adaptation and focus of the lens to focus the light rays of near objects on the retina reaches almost zero, which is a natural phenomenon that occurs in all people due to aging, called presbyopia. The age at which presbyopia starts in a normal state, if the eyes do not have any other problems, is usually around 40 years old. If the eyes do not have other refractive disorders before the onset of presbyopia, such as farsightedness, myopia, and astigmatism, at the time of presbyopia, in addition to the fact that people see the image of near objects blurry, while doing tasks such as reading, working with mobile phones and computers, sewing, delicate tasks, and other tasks where a person needs to focus at a close distance, they will quickly experience eye fatigue, burning, redness, and finally headaches, and the quality of life will decrease day by day. .

Presbyopia is actually not considered a weakness of the eye and unlike other eye weaknesses such as farsightedness, nearsightedness and astigmatism, which occur due to refractive errors of the cornea, lens and transparent environments of the eye, in the phenomenon of presbyopia, there are no refractive errors in the cornea, lens and transparent environments of the eye, and the eyes have a completely normal function from this point of view. The symptoms and vision problems in presbyopia are almost the same as hyperopia, with the difference that hyperopia occurs due to the refractive errors of the cornea and transparent environments, but presbyopia occurs due to the reduction of the power of the eye cilia and the reduction of the elasticity of the lens, and because in this case the cornea, lens, aqueous humor and vitreous are completely transparent, so we do not have any abnormal light refraction. It is not included in the definition of eye weaknesses.

Presbyopia correction

Nowadays, with the help of great scientific advances, in addition to prescribing glasses, other methods such as contact lenses and surgery can also be used to correct presbyopia. The best, simplest and cheapest way to correct presbyopia is to prescribe glasses, and all the problems of a presbyopic person can be completely solved by prescribing a suitable pair of glasses and making standard glasses. In the second step, people with presbyopia who want to have clear near and far vision at the same time and do not want to use glasses for any reason can solve their problem by prescribing special lenses. Therefore, the use of contact lenses for presbyopia, in addition to the fact that the person must observe all the hygiene points, will also have a higher cost than glasses. The third step is to use new surgical methods, which corrects the presbyopia problem by putting a special diaphragm in the eye. As a result, the use of surgical method, in addition to being a very expensive method, cannot be performed in all centers.

Binocular examinations in presbyopia

People who are in presbyopia and have problems with their near vision, if they do not have any other underlying diseases, such as eye diseases or systemic diseases such as diabetes, blood pressure, and thyroid, and appropriate glasses are prescribed for them and standard glasses are made for them at an accredited center, they should usually return for re-examination every two years, but considering that at the age of onset of presbyopia, they may have other eye problems. like glaucoma, it is better for these people to be checked and examined every six months in order to identify and treat any diseases and other problems.

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