There are some excellent designs, including aspherics, translating lenses, translating-aspherics and decentered DeCarle designs. The N series is primarily best for near correction, with a small distance central zone that provides better near acuity. Here are some pearls to help you fit presbyopic patients in fewer tries, using monovision, modified monovision, soft bifocals, RGP aspheric bifocals and translating RGP bifocals. So, if your eyes are not corrected to work together, you will sacrifice some or all of your depth perception.

My Approach.

1) Perform an accurate refraction. with an add power of +2.00D.

Many people notice the effects of presbyopia in their early to mid-40s, as they find themselves holding reading materials at arm’s length in order to focus clearly. Your brain naturally learns to adapt to this setup, where each eye is dedicated to a certain task. Less commonly, some patients will prefer their dominant eye for near, and a small percentage of patients are co-dominant (have no preference). Studies have shown that many patients using monovision contact lenses still retain characteristics of binocular vision and have comparable visual performance. For patients who prefer better near vision and require less distance correction, choose a bifocal lens based on which lenses give better near vision and less distance. The Frequency 55 works well for many patients, but it does have somewhat of a monovision effect to which some patients cannot adapt.
Presbyopia, a word that meant “the elderly eye” in Greek, is a symptom of aging eyes. Toric IOLs changed this completely and gave people a viable treatment option for astigmatism. The biggest advantage of translating bifocal designs is that with proper translation, the incident light has a single focus.

At this time, the surgeon may have made incisions into the cornea to reduce the severity of the astigmatism. Here are some typical problems that arise in fitting translating bifocals, and what you can do to remedy them: Here are some patient requirements in fitting translating RGP bifocals: The following lens requirements must also be met for a successful fit: We owe it to our presbyopic patients to present all feasible contact lens options and go through the painstaking task of fitting the modality best suited to each individual patient"s needs. Bifocal eyeglasses or bifocals: These are the most common solution, where a reading segment is incorporated into the primary lens of the eyeglass. MonovisionEarly presbyopes are excellent candidates for monovision because you only create a small difference in their correction, which most people can tolerate. In many cases, it provides the best vision of all the bifocal designs. Monovision contact lenses involve an adjustment period, which is an important consideration if you’re starting or switching contact lenses. Multifocal contact lenses: These are contact lenses that, like bifocal or progressive eyeglasses, have multiple focal points. You fit these with base curves steeper than the cornea, which may cause some corneal distortion immediately after removal. So, when you prescribe full distance power, fitting a D series on the dominant eye will generally provide better distance vision, while on the non-dominant eye the N series will yield better near vision. This requires, first of all, a thorough knowledge of the lens options available and a willingness to do what it takes to attain a happy outcome. The following is a list of rules that I keep in mind when fitting presbyopes. It is imperative that those who fit presbyopes are aware of the many lens designs and understand which lenses work best on particular types of patients. A good choice might be an Acuvue bifocal +2.00D distance and an add of +1.50D, or a CooperVision Frequency 55 Bifocal N series with distance of +2.00D and an add of +1.50D. On the dominant eye you could fit a CIBA Progressive +2.75D, and on the non-dominant eye you could use a CIBA Progressive +3.25D. Modified monovision: In this variation, a single vision contact lens is worn on the distance eye, and a bifocal contact lens is worn on the near eye. Some patients are very happy with monovision, while others do not tolerate it well. The first thing to remember is to Keep It Simple.

Photograph Simulating Vision With Distance Eye: Photograph Simulating Vision With Near Eye: Photograph Simulating Vision with Eyes Used Together: © Vision Information Services, LLC, Mooresville, NC 2012, Introductions to Cataracts and Cataract Surgery, Causes and Risk Factors for the Development of a Cataract, Determining When to Have Cataract Surgery, Multifocal and Accomodating Intraocular Lenses, Other Important Points about IOLs and Glasses. We have a wide variety of contact lenses from which to choose, but no single modality will work for every patient. Monovision is the term used when one eye is corrected for distance vision, and the other for near vision. The D series is primarily distance correction, with a small central bifocal zone that provides better distance acuity. Monovision contact lenses are one of several common ways that people correct for presbyopia as they age. In disposable lenses, we have three choices. In my experience, the bifocal lenses that favor distance vision are the CIBA Progressive, Cooper Frequency 55 D series, Blanchard"s Esstech PSD and Ideal"s Polyvue. He is a past chair of the Cornea and Contact Lens section of the American Academy of Optometry, and has lectured and written extensively about the use of bifocal contact lenses in clinical practice. Some tips for correcting a presbyope with monovision contact lenses: Modified MonovisionIf the patient still has not adapted to monovision after several adjustments, try modified monovision before moving on to a bifocal contact lens correction. In most cases, the dominant eye (the eye you preferentially look with) is corrected for distance. Therefore, there is no additional out-of-pocket expense to patients choosing this option. In early presbyopes with add power up to +1.50D, correct the dominant eye for distance with a sphere and the non-dominant eye using a bifocal with full distance correction in the bifocal and an add equal to what is needed in their spectacle correction. In order to address the difficulty in changing focus between near and far, one contact lens is prescribed for near vision and the other contact lens for distance. In addition to monovision contact lenses, eye doctors address presbyopia with the following. Monovision LASIK is a compromise; to achieve better near vision, you have to give up some sharpness in your distance vision. The creation of monovision is achieved with two different strength monofocal IOLs. Less commonly, some patients will prefer their dominant eye for near, and a small percentage of patients are co-dominant (have no preference).
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Practitioners need to become more familiar with RGPs. If near vision is a priority, you might try Acuvue bifocals first; if the distance vision is satisfactory, consider starting the patient with this design. Dr. Yager is in a group practice in Orlando, Fla., specializing in contact lenses. Monovision is the name given to the art and science of fitting contact lenses on a patient who has developed presbyopia. It is recommended that all patients who use monovision have a pair of glasses that fully correct them for driving and other activities where maximum visual acuity is of particular importance. It is almost impossible to predict who will favor monovision and who will not. All rights reserved. If you elect to have monovision, and find you do not like it, you can have it reversed after surgery with contact lenses, laser vision correction, an IOL exchange, or a piggyback IOL. Back-surface aspherics are most commonly used. To satisfy the visual demands of an increasingly large contingent of baby boomers in their forties and fifties, clinicians must be knowledgeable about the various contact lens designs available to correct presbyopic patients. There are times when you cannot satisfy a patient"s visual needs with disposable lenses. Copyright © 2020 Jobson Medical Information LLC unless otherwise noted. If you go too long without using your depth perception at all, you can lose it permanently. A prescription for reading glasses to be worn over standard prescription contact lenses for normal (distance) viewing.

Soft Bifocal Contact LensesFor older presbyopes who require an add power of +1.50D to +2.25D and for those who are unsuccessful with monovision or modified monovision, consider fitting bifocal lenses on both eyes. A discussion of LASIK with a patient over 40 becomes more extensive than the usual preop consultation because the surgeon has to address both the patient’s distance vision and the current, or impending, loss of accommodation. We all know that RGP lenses provide the best acuity, so why don"t we fit more of them? In the past, intraocular lenses were not capable of correcting astigmatism when used to replace the lens removed during cataract surgery. In order to have depth perception, you must use both your eyes together. Here are some important points about back-surface aspheric bifocal lenses: The double-aspheric design has an aspheric curve on both the front and back surface. As you age, the lens of your eye becomes increasingly rigid and inflexible: it can no longer adjust its shape as easily to allow you to focus on both near and distant objects. (Usually, your dominant eye will be designated for regular, or distance, vision.). Nothing in this article is to be construed as medical advice, nor is it intended to replace the recommendations of a medical professional. But what are they and how do they work? It comes in two designs, with three add powers available for each. This approach favors the dominant eye for distance and the non-dominant for near. RGP Aspheric Bifocal Contact LensesRigid gas permeable (RGP) bifocals are the best option when you need excellent vision both at distance and at near. Another way to to use this approach--for example, with the Acuvue bifocal--is to use a lens on the dom inant eye with a power of +2.00D and an add power of +1.50D, and on the non-dominant eye a lens power of +2.00D and an add power of +2.00D. If none of these types of fittings satisfies the patient"s needs, you may have to use what I call a modified bifocal fitting technique. In that case, try other designs that are not disposable. Monovision is helpful for near-vision tasks such as scanning a menu or article, but not for reading fine print or reading for a prolonged period of time.

However, if you decide you do not like your monovision, and you elect to have laser vision correction to reverse it, that procedure would not be covered by your insurance company. Monovision contact lenses involve an adjustment period, which is an important consideration if you’re starting or switching contact lenses.

The first sign of presbyopia is the need to hold reading material, especially smaller print, further away than you used to.

Modified Monovision If the patient still has not adapted to monovision after several adjustments, try modified monovision before moving on to a bifocal contact lens correction. Among the bifocal lenses that usually favor near vision are the CooperVision N series, Acuvue, Blanchard"s Esstech PS and Unilens"s Softsite. If you and your eye doctor choose monovision contact lenses, he or she can help make sure that the contacts suit your individual eyes, vision and context.