Are there any Good Soft Bifocal Contact Lenses?

As the baby boomers age those who are wearing contact lenses are realizing they can't see like they use to at near distances! This invariably is noticed in their early 40's depending on their visual demand on their eyes. With the prevalence of computer in the work place and home, more and ore baby boomers come in to the office complaining of near point blur. This is due to the aging changes of the crystalline lens of our eyes hardening with age. They become too rigid to flex and focus with time. This condition is known as presbyopia.

Contact lens manufacturers recognize that the presbyopic baby boomers are the fastest growing segment of contact lens market today. As a result great efforts have been made to develope effective bifocal contact lenses of the soft variety. There have been many rigid gas perm designs over the years but for any rigid gas perms, comfort is always a big obstacle to successfully wearing these lenses.

For the past 30 years monovision has been the primary technique to soft lens fitting for the presbyope. This technique involves correcting the dominant eye for distance and the non-dominant for reading. This technique is still commonly used today as it is the least expensive technique. The drawback of this technique is that as the patient ages he requires more help at near and the disparity in power and vision between the two eyes becomes to great. The vision at distance suffers. There is also a loss of depth perception or binocularity.

Several manufacturers have developed soft bifocal contact lenses. B&L"s Purevision multifocal is made of a silicone co-polymer which is the most rigid of the soft bifocal lens materials. This makes comfort an issue for some patients but durability is outstanding.

My favorite soft multifocal is Ciba's Air Optix Aqua Multifocal. This lens is available in 3 bifocal add power levels and also incorporates a chemical that attracts water to the lens. This is a very nice attribute because with increasing age comes decreased tear production.

These first two lenses are a center near design. This means that the center of the lens has the reading power with a skirt of the distance power. For these lenses pupil size is important. A small pupil restricts light passing through the distance power of the skirt of the lens. Consequently they end up looking through the reading power only. Therefore small pupils are a contraindication to these contact lenses.

Another popular brand is Cooper's Proclear Multifocal. This lens is unique in design. In one eye the center of the lens is the distance prescription with a skirt of reading. The other eye is just the opposite, center near with a skirt of distance. This is an excellent lens with a wide range of bifocal add powers. Cooper is the only company to provide a multifocal lens for patients with astigmatism. These are made to order and quite expensive but a nice option with 2 base curves or shapes.

Johnson & Johnson's Acuvue has a nice bifocal contact lens. Though made with a 1980's lens polymer, it does come in a steep base curve to address that portion of the population that have very curved corneas. I don't use this one too often because it is a 2 week disposable and pretty thin is the low lens powers. Durability is an issue. Acuvue does have a new bifocal design made in same material as the Oasys lens with Hydraclear to increase permeability and lens hydration. It was introduced in Europe. I have no experience with this new lens but have great success with the Oasys lenses.

Success rates in fitting these lenses is about 50% which is poor by fitting standards but at least there are options to try. In years past we would just say "wear reading glasses over your contacts." Many people still do just that now. Other factors affecting success involve the patient having too much astigmatism and not being able to see clearly at distance or near. Corneal curvature varies greatly across the population and most manufacturers make only one shape to fit the greatest number of peapole. So if you have a very curved eye,most bifocal contacts will not fit properly. These lenses are some of the most complex contact lens designs and some of the most expensive. For some they are prohibitively expensive.

There are more options available for patients and practioners today than ever before. Next time you are in for a contact lens evaluation, ask your doctor about multifocal contact lenses.