تعریف پیرچشمی
همه چشم ها به صورت طبیعی دارای یک عدسی شفاف محدب الطرفین هستند که در پشت عنبیه واقع شده است و از طریق رشته های باریکی به نام زونول به ماهیچه های مژگانی متصل میباشد . عدسی چشم انسان همانند یک عدسی دوربین عکاسی که با چرخاندن و فوکوس باعث وضوح تصویر میشود و با انقباض ماهیچه های مژگانی باعث تغییر تحدب عدسی چشم میگردد . به این عمل تغییر تحدب عدسی چشم در اثر انقباض ماهیچه مژگانی تطابق میگویند . زمانیکه چشم ها به اشیا در فواصل مختلف نگاه میکنند عدسی چشم که خاصیت ارتجاعی دارد تصویر اشیاء را با تغییر تحدب عدسی بر روی شبکیه کانونی میکند و باعث میشود افراد اشیاء را در همه فواصل واضح ببینند . به مرور زمان و با افزایش سن خاصیت ارتجاعی عدسی چشم و قدرت ماهیچه مژگانی کاهش پیدا میکنند و میزان تطابق و فوکوس عدسی برای کانونی کردن پرتوهای نوری اشیاء نزدیک بر روی شبکیه تقریبا به صفر میرسد که به این پدیده که یک امر طبیعی میباشد و در همه افرادبر اثر بالا رفتن سن اتفاق می افتد پیرچشمی میگویند . سن شروع پیرچشمی در حالت نرمال در صورتیکه چشمها مشکل دیگری نداشته باشند معمولا حدود چهل سالگی میباشد . If the eyes do not have other refractive disorders such as farsightedness, nearsightedness and astigmatism before the onset of presbyopia, at the time of presbyopia, in addition to the fact that people see the image of near objects blurred in doing tasks such as reading, working with mobile phones and computers, sewing, delicate work and Other tasks that a person needs to focus on at a close distance quickly lead to eye fatigue, burning, redness and finally headaches, and the quality of life decreases 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
Today, with the help of great scientific advances, presbyopia correction can be done by other methods such as contact lenses and surgery Used to correct age spots. 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 the use of new surgical methods, which corrects presbyopia by placing a special diaphragm in the eye. As a result, the use of surgery, besides 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 in an accredited center, they should usually return for re-examination every two years, but considering that at the age of onset Presbyopia may also have other eye problems, such as glaucoma. It is better for these people to be checked and examined every six months to identify and treat any diseases and other problems.
