Bifocal Contact Lenses contain two prescriptions in the same lens and are usually used to improve the eyesight of those with “Presbyopia”, an age-related problem with vision that affects the eye's lens, or astigmatism involving curvature of the eye's lens. Presbyopia is recognized by the need to hold reading material farther off than usual so that the print is clearer. The lenses prescribed for this can be bifocal or monovision and both are available as soft and rigid lenses.
Bifocal contact lenses are available as soft lenses and rigid gas permeable lenses, besides disposable contacts where they can be discarded after a specific period of use and replace them with new ones. Today, a number of manufacturers make multifocal lenses from silicone hydrogel material that allows more oxygen into the cornea when compared to the traditional contact lenses.
How bifocal contact lenses are designed
Like the traditional bifocal glasses, contacts also have the distance and near prescription in one lens. Some people opt to wear monovision contacts where one eye has the distance correction and the other has the near vision correction. For those who are used to wearing contact lenses, it is easier to get accustomed to bifocals. Another solution is wearing reading glasses while using distance contact lenses. A number of options are available and the most important thing is to find a professional who can recommend the right one for your needs.
There are many bifocal contact lens options. A professional fitting and evaluation is necessary to determine which design is right for you as each lens must be personalized based on your vision correction needs.
There are two types:
Translating – also known as alternating lenses where the pupil can switch between both the power areas while looking up or down. The distance power is on the top half and the near power is in the bottom half of the lens. If one were to read a book, the lower half would enlarge the print, making it easier to read.Simultaneous lenses allow the user to see both distant and near objects with the same lens and can be aspheric or concentric lenses. Aspheric can have multiple power prescriptions and are called progressive lens. Concentric lens, as the name suggests, has the power in concentric circles. Based on the prescription for each individual's vision, the location of the power varies on the lens.
The best candidates for bifocal contact lenses are those who do not have dry eyes and have a healthy cornea, blink normally and can wear their lens during the day time comfortably. The process of adjusting to these can take some time. Some opticians offer free trial contacts for quicker acclimatization. An accurate prescription is based on the pupil size and near prescription details.
The biggest benefit of bifocals is you need not carry two pairs of glasses and keep switching from one to the other throughout the day. The variety available today makes it much easier to access better vision enabling the wearer to see better and enjoy all the everyday activities more comfortably.