Introduction
Presbyopia is not a frightening condition. It is a condition characterized by the eyes' inability to see the objects present nearer. It occurs due to the age-related hardening of the lens of the eye (a healthy lens is more flexible and lets us focus on objects nearer and farther). It is more common in older people (above 40). The word presbyopia is derived from the Greek word 'Presby,' meaning old people, and 'opia,' meaning eye. It can easily be corrected with eyeglasses, contact lenses, and surgery. The presence of presbyopia will be noticed while reading newspapers or books, and the affected people will tend to keep the reading material away from seeing clearly. Presbyopia is often mistaken for farsightedness. However, both conditions are different. Presbyopia is caused due to alterations in the lens of the eye. At the same time, farsightedness is caused by the shortening of the eyeball.
This article will discuss the causes, symptoms, diagnosis, and management of presbyopia in detail.
What Causes Presbyopia?
The vital function of the eyes is vision. An eye consists of several layers like cornea, lens, retina, etc., to work together and produce an image for vision. The light reflected from an object will enter the dome-shaped corneal layer, passing through the flexible clear lens and reaching the retinal layer, where the signals are sent to the brain to produce an image.
The flexible lens layer is surrounded by muscles that help to focus nearer and farther images. To focus the nearer objects, the muscle will constrict, and to focus the farther objects, the muscle will relax. In old age, the lens will harden and lose its flexibility. Thus focusing nearer objects becomes difficult.
What Are the Symptoms of Presbyopia?
Common symptoms of presbyopia are,
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The affected ones will experience blurred vision while reading at an average distance.
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There will be a tendency to hold the reading material at a farther distance.
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There will be a need for extra light to view things.
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Headaches and eye strain are common among people affected by presbyopia due to constantly trying to focus on things placed near them.
What Are the Risk Factors for Presbyopia?
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Age is the foremost risk factor for developing presbyopia. It is a natural age-related condition and most common in people of age above 40 and less than 65. There is no sex predominance. Both males and females are equally affected.
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Few cases of premature presbyopia are recorded globally. It tends to occur in people of age below 40. Premature presbyopia occurs due to underlying medical conditions like diabetes, farsightedness, cardiovascular conditions, and multiple sclerosis. Taking certain medications like antidepressants, antihistamines, and diuretics for a long time can cause premature presbyopia.
How to Diagnose Presbyopia?
An ophthalmologist will suggest taking a refraction assessment test to diagnose what type of eye condition is present, whether it is presbyopia or astigmatism. It also helps the doctor decide what type of glasses to be prescribed.
Dilating the pupils by adding a few eye drops is very common to examine the layers of the eye. The eyes might be sensitive to light after dilation, which will subside in a few hours. Until then, it is advisable to drive around.
First, the doctor will assess the patient’s eye to assess how well the light enters the cornea and is refracted by the retinal layer. With this, a refractive score will be marked.
Then the refraction assessment test will be done by making the patient sit in front of a device called a phoropter. Twenty feet from the patient, a chart containing alphabets and numbers will be placed. It has various lenses of different strengths, and the patient's vision through each lens is assessed. The doctor will ask the patient to tell which lens provides more precise vision. One eye is checked at a time. Finally, the doctor will devise a treatment plan that provides 20 / 20 vision.
How to Treat Presbyopia?
The presbyopia treatment will include prescribing appropriate eyeglasses, contact lenses, refractive surgeries, or lens implantation.
Eye Glasses -
Eyeglasses are found to provide amazing results. To begin with, over-the-counter non-prescription reading glasses can be used, in case no other eye problems are associated with presbyopia and there were no eye problems present before developing presbyopia. Non -prescription glasses’ power ranges from +1 diopter to +3 diopter. Appropriate glasses should be chosen by trying on glasses with different lenses and power until proper magnification is obtained and a more precise image is seen.
In cases where over-the-counter non-prescription glasses do not work, prescription glasses should be worn. Prescription reading glasses are used only for reading purposes when no other eye problems are present.
There are a few glasses available in case multiple problems are present, and they are,
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Bifocals are glasses present with a horizontal line visible to the naked eye. The lens above the line is meant for distance correction, and the lower ones are meant for reading.
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Trifocals are seen with two visible horizontal lines meant for distant middle vision, distant vision, and closer vision.
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Another pair of glasses available are called progressive multifocal and are not seen with horizontal lines. But it was meant to provide middle-distance, distant, and close-up vision. Progressive eyeglasses are also available for computer usage purposes.
Contact Lenses -
People who do not want to wear glasses can opt for contact lenses, provided conditions of a tear duct or eyelids are not present.
Bifocal contact lenses, where each contact lens is provided with a lens to support distance and close-up vision, are available.
Monovision contact lenses are also available, where one contact lens will provide distance vision and another contact lens will provide close-up vision. Distance vision-producing lenses are predominantly marked for the dominant eye.
Refractive Surgery -
Refractive surgeries are done to reshape the corneal layer to improve near vision. But in a few cases, the patient may wear glasses for close-up vision even after surgery.
Conductive keratoplasty, laser-assisted in situ keratomileusis (LASIK), laser-assisted subepithelial keratectomy (LASEK), and photorefractive keratectomy are a few refractive surgery procedures available. All these procedures are targeted to reshape the cornea to facilitate proper vision.
Lens Implants -
A Lens implant procedure is available through which the affected lens is removed and replaced by a healthy artificial lens known as an intraocular lens. This surgery is more like cataract surgery and shows some side effects like inflammation, bleeding, and glaucoma.
Conclusion
Preventing presbyopia is not possible. It is an age-related condition, and by taking appropriate treatments, complications can be avoided. If presbyopia is not appropriately managed early, it will significantly affect the quality of life. Seeking a doctor as soon as the first sign is seen will do good.
