Varifocal glasses, also known as progressive or multifocal lenses, are corrective lenses used in spectacles to correct presbyopia, which is a reduced ability to focus on near objects caused by natural aging. They provide continuous vision for all distances in a single lens, correcting both near and distance vision. Varifocal glasses have a gradual change in strength from the top of the lens to the bottom with multiple focal points in between, allowing wearers to see all distances and focus points through just one lens. The top of the lens is for distance vision, the center of the lens is for intermediate vision, and the bottom of the lens is for near vision.

Varifocal glasses are typically used when wearers have two prescriptions, one for distance and one for reading. They can help reduce the number of glasses needed and provide a more natural vision experience than bifocal lenses, which have a visible line separating the two prescriptions. However, it may take some time to adapt to varifocal glasses, and wearers may experience symptoms such as eye strain, headaches, dizziness, and nausea during the acclimation period.

Varifocal glasses can be customized to meet individual needs, and lens designers have more flexibility in optical design trade-offs than with parfocal zoom lenses. The latest designs have wider fields of vision and less edge/peripheral distortion, making them easier to adapt to.