There are three main types of optical lenses: single vision, bifocal/trifocal, and progressive.
TYPES OF OPTICAL LENSES
Single Vision
Single vision lenses offer only one type of vision correction: correcting myopia (near-sightedness) or hyperopia (far-sightedness). These lenses have the same prescription power across the entire lens.
TYPES OF OPTICAL LENSES
Bifocal/Trifocal
Bifocal lenses contain two different prescriptions to correct both near and far-sighted vision. The upper section allows for distance vision, and the lower section aids with close up focus. Bifocals have a visible dividing line between the two prescriptions. Trifocal lenses have the same concept as bifocal lenses, except that there are a total of three prescriptions.
The top section is for distance vision, the bottom section is for close up focus, and the middle section is for vision that lands in between the two. For example, computer work would land in the middle section.
TYPES OF OPTICAL LENSES
Progressive
Progressive lenses are a popular choice over bifocals and trifocals as they correct vision at near, middle and far distances with no visible divide. A progressive lens changes power gradually from the top of the lens to the bottom, making it a smooth transition between prescriptions. This gives the advantage of offering clear vision over a large range of distances.
