Secrets to enjoying your eye-sight after 40 even on being diagnosed as having presbyopia
Author: Dr Anitha Arvind
In this article, you will understand what is presbyopia and what can you do to manage it effectively.
Figure 1: Presbyopia: it’s as normal as greying!
Presbyopia is a condition resulting in a gradual loss of the eye’s ability to focus on near objects. This is a part of normal ageing as the crystalline lens hardens/stiffens with age. The muscles that hold the lens in place become weaker. The ability of the lens to accommodate or change its shape and therefore its power diminishes, resulting in presbyopia.
Presbyopia sets in around 40 years of age and progresses after that. It is an unavoidable ageing condition of the eye, and the age at which it sets in varies in people. Presbyopia can be easily diagnosed during a routine eye examination, and several options are available to correct presbyopia and restore near vision.
Symptoms of presbyopia:
The following are one or more of the symptoms experienced by the presbyopic population:
• Progressive difficulty in performing near vision tasks like reading small print, reading print from digital devices etc.
• Tendency to hold the reading material (books/newspaper/digital screens) farther away to make the print visible.
• Complaint of headache, eyestrain or tiredness after prolonged reading or near work.
• Blurred near vision at usual working/reading distance, which gets aggravated under dim illumination
• Short-sighted (Myopic) people tend to remove glasses to do their near work, but as presbyopia advances, they face difficulty in near work at the usual near working distance
Figure 2: Headache and eye strain are common in ucorrected presbopyes after long hours!
Presbyopia can be diagnosed during a simple eye examination wherein reading the small print on a near vision chart becomes difficult when presented. The practitioner determines the amount of presbyopia, and a suitable corrective power is prescribed.
The presbyopic correction for an individual is mentioned as ‘Addition’ or ‘add’ in the prescription. Presbyopia can occur in isolation or along with other refractive errors (if present) like myopia (short-sightedness), hyperopia (farsightedness) and astigmatism (cylindrical correction).
There are several options available for correcting presbyopia and are listed below:
1. Eyeglasses for presbyopia:
Eyeglasses are the most straightforward and standard means of correction of presbyopia globally. It is also the cheapest way of correcting presbyopia. There are several eyeglass options available for correction of presbyopia, namely:
Single vision eyeglasses: These glasses have only the presbyopic correction and are to be used only during near vision activities like reading, writing, needlework etc. This is a good option for those who only have a presbyopic correction and no other associated refractive errors. The flip side is that the glasses have to be removed every time distance objects have to be seen.
Figure 3: Presbyopia spares no one, not even Santa!
Bifocals: The bifocal lenses have a distance prescription and near incorporated in them. The near prescription meant for correcting presbyopia is incorporated in a segment, so a dividing line demarcates the distance and near vision prescription.
Figure 4: Small fonts? Fret not. Glasses to the rescue!
The wearer has to use the reading segment for near vision activities. The dividing line is visible to the wearer and the onlooker. Several designs of bifocal segments are available, namely round segment, D segment and Executive bifocals, each having its pros and cons. An optometrist or optician can recommend the right bifocal based on the wearer’s prescription, lifestyle, and preferences.
One major drawback of bifocals is that the power correction can only be made for two distances. So bifocals can be – distance and near, where the intermediate or computer-distance vision will be unclear, or distance and intermediate, where the near would be unclear, or Intermediate and near, where the distance vision would be unclear.
Trifocals: These glasses, as the name suggests, has three segments incorporating prescription and clear vision for three distances, namely distance vision, intermediate vision and near vision.
These are not popular since they have two visible dividing lines on the glasses, causing discomfort to the wearer and cosmetically not an excellent choice for wearers. These were the glasses of choice for those requiring intermediate correction (for working on the system) before the advent of progressive lenses.
Figure 5: Types of eye lenses available
Progressive lenses: These glasses are the most popular and preferred choice of glasses for presbyopia globally.
The progressive lenses offer the advantage of providing vision correction for distance, intermediate and near without any dividing line on the lenses and look like a single vision glass, thus offering a great cosmetic appearance to the wearer.
There are several progressive lens designs and brands available in the market, each having its pros and cons. The progressive lenses are made with advanced technology and are cosmetically superior to any lenses hence more expensive than other lens options available.
The progressive lenses are customizable to the wearers’ needs, lifestyle and preferences. An optometrist or an optician is trained to dispense these lenses; hence, it is best to get a pair of progressive lenses recommended by them.
Office lenses: These lenses are also a type of progressive lens design that incorporates vision correction for intermediate and near use. These lenses are beneficial to those who have correction only for near but work in a static environment using the computer/laptop at an intermediate distance and perform near work.
These lenses are not to be used while walking or driving. A wide variety of office lenses and brands are available, taking into account the wearer’s various visual demands.
They provide superior near and intermediate vision compared to progressive lenses, but as the distance power zone is missing or very limited, they are the extra pair and are restricted for office use.
2. Contact lenses for presbyopia:
Contact lens options for presbyopia are available in various designs and brands. However, the suitability of the wearer to contact lenses needs to be examined before going in for a contact lens.
A contact lens practitioner would conduct a thorough examination to check for the eye’s suitability to contact lenses, discuss the wearer’s lifestyle and preferences, followed by a trial fitting with contact lenses before recommending and dispensing contact lenses for presbyopia.
Figure 6: Unlike popular opinion, contact lenses are also prescribed for presbyopia
The contact lenses for presbyopia are also available in different wear modalities such as daily disposables for occasional use, fortnightly disposables, and monthly disposables depending upon the wearer’s preferences. The types of contact lenses for presbyopia are as follows:
a) Bifocal contact lenses: These lenses have power incorporated to provide vision for distance and near work. These lenses are available in soft and rigid gas permeable materials.
b) Multifocal contact lenses: These are the most commonly prescribed contact lenses for presbyopia worldwide. These lenses have power incorporated to provide clear vision for distance, intermediate and near work use, similar to progressive lenses. Several brands and designs are available in soft materials for multifocal contact lenses. They are also available for those wishing to use them occasionally for a specific purpose such as social functions etc.
c) Monovision contact lenses: These lenses have different prescriptions for each eye so that one eye (mostly the dominant eye) is used for distance vision and the other eye for near vision. The contact lens practitioner will decide which powered lens goes to which eye after conducting a couple of tests to determine the dominance of the eyes. Suitability for this option has to be assessed, as it may not be an option for everyone. These types of lenses were popular before the advent of multifocal contact lenses.
d) Enhanced or modified monovision lenses: In this, a multifocal or bifocal contact lens is prescribed for one eye, and a distance powered contact lens is prescribed to the other eye. So, both eyes are used for distance vision, and one eye is used for near vision.
3. Surgical options for presbyopia:
A couple of surgical options are available for the correction of presbyopia. However, a thorough examination by an ophthalmologist trained and experienced in performing such refractive procedures can only give the final recommendation. Each surgical option has its pros and cons and must be thoroughly explored before deciding. This field is ever-evolving with newer techniques available with advancements in science and technology. The following are a couple of surgical options which are recommended.
Figure 8: Although not common, Eye surgery is an option for management of presbyopia
a) Laser-Assisted In-situ Keratomileusis (LASIK)/ Laser-Assisted Sub-epithelial Keratectomy (LASEK): In both procedures, the surgeon creates a thin flap using LASER beams to reshape the cornea to correct for presbyopia. Both the procedures are relatively painless and have a faster recovery. A monovision LASIK improves distance vision for one eye and near vision for the other eye.
b) Conductive keratoplasty: This procedure is also called near vision conductive keratoplasty. Radio waves are targeted at certain spots on the cornea to reshape and increase its near focusing ability. This is not a long-lasting procedure, and the results may be variable.
c) Corneal inlays: This procedure involves placing tiny implantable plastic rings within the cornea to improve vision due to presbyopia. Several corneal inlays are available, and the best option needs to be discussed with the ophthalmologists, who will also decide based on the suitability of the eye to this procedure.
d) Lens implants: In this procedure, the surgeon removes the natural lens within the eye and replaces it with an artificial lens called the Intra Ocular Lens (IOL) to correct for presbyopia. The lens implants could either create monovision (one eye used for distance and the other eye for near) or be multifocal in which both eyes are used for all distances. The surgeon decides the best option for the patient.
Conclusion: Presbyopia is a natural and unavoidable age-related progressive condition. The diagnosis of this condition is straightforward, and there are several options available for correction of this condition. Not everybody turns presbyopic at the same age and varies from individual to individual. Yearly eye examinations are recommended for everybody post 40 years of age.