Presbyopia Correcting

Eyeglasses for Presbyopia

One of the most common treatment options for presbyopia is bifocal, trifocal or progressive lens eyeglasses.

• Bifocal Lenses: A bifocal lens is split into two sections - one for seeing distant objects clearly and a second power in the lower half of the lens for seeing clearly at a specific reading distance. The larger, primary section corrects for distance vision, while the smaller, secondary section allows you to see up close. The junction between these distinctly different power zones is defined by a visible 'bifocal line' that cuts across the centre of the lens.
• Trifocal Lenses: As the name suggests, trifocal lenses have three power zones to offer correction for near and far vision, but also enables a person to see clearly at an intermediate level.
• Progressive Lenses: Progressive lenses, on the other hand, function in a similar manner to bifocal and trifocal lenses, except that the sections of the lens optimised for distance and near vision are more blended (as opposed to the two or three distinct zones that characterise bifocals and trifocals).

Contact Lenses for Presbyopia

There are two different types of contact lenses for people with presbyopia; multifocal contacts and monovision contacts.

• Multifocal Contacts: To provide clear vision across various focal points, multifocal contact lenses have several rings or zones set at different powers. With this design, although you are actually using both near and far vision at the same time, these lenses provide clear vision at different ranges when the brain learns to automatically select the right focus for what you want to see.
• Monovision (Blended Vision) Contracts: These correct one eye for distance and one eye for close-up vision. Since visual acuity and depth perception can be affected, multifocal contact lenses can be problematic for some people who find it difficult making the adjustment.

1. Refractive Lens Exchange (Lens Replacement Surgery)

Using Presbyopia Correcting Intraocular Lenses (IOL's)

To correct the refractive error and restore near focus, refractive lens exchange replaces the ageing lens of the eye with an artificial intraocular lens (IOL). This procedure can be performed on one or both eyes and offers an effective solution to presbyopia.

Since refractive lens exchange uses the same technique as cataract surgery (where the eye's natural lens is replaced with an artificial intraocular lens), this means that the chance of developing cataracts in the future is eliminated. Another advantage of lens replacement surgery is that due to the fact that multifocal IOLs are implanted inside the eye, they do not require any care or routine replacement like contact lenses do.

Although refractive lens exchange is a more invasive procedure compared to laser alternatives, it is usually best suited typically for patients over 50 with presbyopia or extreme farsightedness. There are a number of lens replacement options available, however, the two most common IOL's used to correct presbyopia include:

• Multifocal Lenses: A multifocal lens provides clear vision at several distances
• Extended Depth of Field (EDoF) Lenses: These IOL's spread focused light over a greater distance allowing patients to have a more continuous range of vision without the possibility of 'gaps' in the vision. They are also less likely to induce night vision haloes or starburst effects than Multifocal IOL's.

Lens Replacement Surgery For Monovision/Blended Vision

Patients who have issues with both distance and near vision may greatly benefit from exploring monovision correction achieved with lens replacement surgery. Monovision is a type of correction where one eye is corrected for distance (typically the dominant eye), and the other eye is corrected for near vision, which works due to neuroadaptation.

Neuroadaptation is the process where your brain is able to comfortably process the distant and near images, to work together to see at all fields of vision. Overall, the images from both eyes are processed by your brain as one blended image.

Most people who have monovision find that they adjust within a matter of days and many can get rid of their glasses. However, since not every brain and person will accommodate to monovision, the patient will usually be required to trial monovision contacts or glasses before considering monovision refractive lens exchange surgery.

2. Laser Technology

Refractive surgery works by changing the shape of the cornea in order to adjust the refractive power of the eye. The two different types of refractive surgery available to treat presbyopia include Monovision/Blended Vision LASIK and PRESBYOND Laser Blended Vision. Monovision/Blended Vision LASIK and PRESBYOND are non-invasive laser eye surgery procedures, which are performed using blade-free femtosecond and excimer laser technology.

• Monovision/Blended Vision LASIK: For the treatment of presbyopia, the dominant eye is treated for distance vision and your non-dominant eye is treated for close vision (reading) eliminating the need for all types of glasses. While many patients find that they adapt well to this technique and with both eyes open cannot tell which eye is set for distance and which eye is set for near, monovision/blended vision LASIK is not for everyone. Some people find they simply cannot adapt to it. For this reason, eye doctors usually recommend trying monovision with contact lenses first before committing to monovision/blended vision LASIK surgery for presbyopia correction.
• PRESBYOND Laser Blended Vision: One of the most effective and least invasive methods for addressing presbyopia is PRESBYOND Laser Blended Vision, and most people with presbyopia are suitable for it. PRESBYOND can be effective for treating a wide range of myopic, hyperopic, astigmatic and even emmetropic (normal distance sight) presbyopic patients.