Bifocal and multifocal contact lenses are designed to correct vision at all distances for people suffering from vision issues and presbyopia (age-related decline in near vision).
Bifocal contact lenses have two separate prescriptions within the same lens, while multifocal contact lenses have a range of prescription powers in each lens (similar to that of progressive eyeglasses.)
“Multifocal contacts” is also often used as a catch-all term for all types of contact lenses with more than one prescription power, including bifocal lenses.
Unlike simpler contact lenses that use a single prescription strength to correct a single problem (such as near vision difficulty), bifocal and multifocal contact lenses can correct multiple issues with a single pair of lenses. There are two primary types of multifocal lenses:
Segmented: This design functions like bifocal and trifocal eyeglass lenses. The central and upper portions of the lens have the correct power for distance viewing, while the lower portion is geared toward viewing near objects. Depending on whether the wearer is focusing on a near or far object, the eye will look through the correct segment. (Segmented trifocal designs, which also have a portion dedicated to intermediate vision, are also available.)
These contact lenses are always rigid gas permeable lenses, and function properly because unlike soft lenses, which move with the eyes, these are designed to stay in a set position over the eye, which moves behind it.
Simultaneous Vision: This lens design has specific regions on the lens designated for near and far (and sometimes also intermediate) vision. Depending on the distance of the object being viewed, the wearer’s eye will use the region of the lens that gives the sharpest vision. Within this category there are two types of designs; concentric and aspheric.
Falling under the broader category of simultaneous vision lenses, concentric multifocal contact lenses generally have the lens power for distant vision in the center of the lens, which is surrounded by concentric rings of both near and distance powers according to the wearer’s prescription. Most of the time, at least two of these rings are within the area of the pupil in normal lighting. (This can vary as the pupil dilates and constricts based on the lighting around the wearer.
Concentric multifocal contact lenses can be made of either rigid gas permeable or soft lens material, and the locations of the different powers will vary based on this. In gas permeable lenses, the distance power tends to be in the center (center-distant), while soft lenses more often have the near power in the center (center-near).
Additionally, another option is to have a lens with a center-distance design for the dominant eye and a center-near configuration for the non-dominant eye.
Consult our eye care professional to determine which option is best for you.
Aspheric multifocal contacts, also a type of simultaneous vision lens, are similar in design to progressive eyeglass lenses, meaning that there is a gradual change in power from far to near, with no hard divide between sections. There are also no visible lines in these lenses, which can be more aesthetically pleasing for some.
Due to the progressive lens design, however, these can take some time to adjust to.
Bifocal and multifocal contact lenses can be made both of soft and rigid gas permeable material. Rigid lenses can be more effective in some respects, but can be more challenging to maintain and less comfortable to wear than soft lenses.
Hybrid contact lenses are also available. These have a rigid lens portion in the center, with a flexible skirt going out around it. This provides the vision benefits of a rigid lens with the comfort of a soft one. However, these can be more difficult to maintain and put on.
For most people, multifocal contact lenses work very well. However, limitations do exist. For example, distance vision might not be perfectly clear, or small print might be hard to read.
For some, other options like monovision contact lenses might be a better choice.
Your eye care professional will be able to advise you on what options are best for your personal needs after completing your eye exam.