Multifocal Contact Lenses: What are they and what are they used for?
Multifocal contact lenses are prescribed to people with presbyopia. This is a vision problem that is age-related and mainly affects people over the age of 40. These lenses also help improve vision for people with refractive errors.
Multifocal lenses are preferred over glasses sometimes since most people in this age bracket engage more in physical activities such as hiking, jogging and exercising. During these activities, it is quite cumbersome to have your glasses on all the time.
Once one attains the age of 40, focusing on close objects becomes difficult. This is as a result of presbyopia. People with the condition have to hold objects such as newspapers away from their eyes so as to focus properly. A simple solution to this is multifocal contact lenses.
What types of Multifocal Contact Lenses are available?
Multifocal contact lenses are made from different materials, mainly soft materials and rigid gas permeable (GP) materials. Hybrid contact lenses are also available. Some multifocal lenses are made from silicone hydrogel material. These provide greater wearing comfort by allowing more oxygen to reach the cornea.
Disposable multifocal lenses are also available. These are disposed after use over specified periods, e.g. daily or monthly, and replaced with new ones. This helps reduce the hassle of lens care on the user.
What are the designs used in Multifocal Lenses?
For people with presbyopia, the most common lens design is the concentric bifocal pattern. This pattern features a small circle at the center of the lens for near correction surrounded by a large circle designed for distance correction. The two circles could be interchanged, depending on the condition of the user.
Other multifocal lens designs include:
1. Alternating image design
This design features distinct zones for distance and near vision within the lens. For this design, the only material used is gas permeable lens material. The top part of the lens is for distance vision with the bottom one being used for near vision. These zones are divided by a nearly invisible line.
When looking straight ahead, the user is looking through the distance portion. When looking down, the lens is supported by the lower eyelid, and the user can make use of the lower portion of the lens for reading.
2. Simultaneous image design
In this design, both the distance and near vision portions are located in front of the pupil on the lens at the same time. Soft and GP materials can be used for this design. When using these lenses, it is up to the brain to determine the area of the lens to ignore and the area to emphasize so as to get the best resolution.
Difference Between Multifocal and Bifocal Lenses
Multifocal and bifocal contact lenses serve the same function, more or less. The difference between the two comes in how they are designed to work. In the case of bifocal contact lenses, they consist of two prescriptions fitted on the same lens. On the other hand, multifocal lenses consist of a range of powers fitted on each lens.
If you are looking to buy multifocal lenses, what options are there in the market today? Here are a few:
1. Dailies Total 1 MF
These are Water Gradient Silicon Hydrogel contact lenses that are designed to provide extra comfort as they feature more than double the water content from core to surface. These lenses are daily disposable soft contact lenses. These lenses are manufactured by Alcon.
2. Aqua Comfort Plus MF
These daily disposable contact lenses feature an outstanding tear film stability and higher moisture content to provide all day comfort. Among the outstanding features of the lenses is blink-activated technology that moisturizes the lenses with every blink and Trademark Light stream Technology that improves the quality of the lens greatly.
3. Air Optix Multifocal
Air Optix multifocal lenses feature permanent plasma technology giving them a smooth, continuous design. They also feature the latest technology in multi-purpose solutions, including Clear Care Plus and Opti-free. All these optimize the wearing experience. These contact lenses are used for presbyopia and are replaced monthly.
4. Biofinity Multifocal
Biofinity contact lenses feature Aquaform Technology that enhances comfort and performance. These lenses are used for presbyopia and are replaced monthly. Balanced Progressive Technology allows for multiple zones of vision correction to be incorporated in both lenses.