Different lens types, something for everyone
Chanté Roets - B.Optom (UOFS) CAS(SA)
Single vision lenses have the same prescription throughout. The single focus of the lens sharpens your vision when focusing on either nearby objects or faraway items, but not both.
Bifocal lenses sharpen your vision for both nearby and faraway objects. The upper part of a bifocal lens focuses on faraway objects while the bottom part of the lens focuses on close-up objects. The result is clear vision at both distance and near with one pair of glasses. While bifocal lenses often contain visible lines or segments differentiating the areas of contrasting prescriptions, they are a great choice for some people who desire a wider lens area for reading and far viewing. You can also get a bifocal lens without the visible line, called an invisible bifocal lens.
Multifocal lenses have three focus points which focus on far objects at the top of the lens, on intermediate objects like computer screens in the middle of the lens and on close-up objects at the bottom of the lens. Multifocal lenses gradually change power from the top of the lens to the bottom, giving a smooth transition from distance vision to intermediate/computer vision to near/reading vision.
An accommodative support lens has a similar design to that of a multifocal lens, but is used in patients younger than 40 years of age. The lens will support the patient’s accommodation system during near tasks throughout the day due to additional plus power at the bottom of the lens.
Office lenses are a type of multifocal spectacle lens, designed for close-up and intermediate use and are intended to provide clear vision at around 40cm to about 2 - 4m.
Speak to your optometrist to find out whether one of the above lenses is an option for you.