Gleitsicht

Gleitsicht describes a type of eyeglass lens known in English as a progressive addition lens. It provides a gradual change in optical power from the top to the bottom of the lens, enabling clear distance vision at the top, intermediate vision in the central zone, and near vision at the bottom. This design allows wearers to see across distances without the conspicuous lines found in bifocals or trifocals.

Construction and design: Gleitsicht lenses are ground with a continuous surface that creates a smooth power progression. Several designs exist with different corridor lengths and rates of power change, affecting field of view and peripheral distortion. The near addition typically ranges from about 1 to 3 diopters and is customized to the wearer’s prescription. Frame choice and proper fitting are crucial; frames must allow the intended corridor and the optical center must align with the pupil. A fitting height is measured to position the zones correctly.

Usage and adaptation: They are commonly prescribed for presbyopia and for people who require both distance and near correction. Adapting to a progressive lens can take days to weeks, during which users may experience peripheral distortion or a sensation of movement known as “swim” until the eye learns to converge with the new optics. They can be more expensive than single-vision or lined multifocal lenses.

Maintenance and availability: Today Gleitsicht lenses are produced by many manufacturers in a range of designs, coatings and materials. Regular cleaning with a soft cloth and lens cleaner, proper storage, and periodic check with an optician help ensure correct alignment and performance.