Bioptic telescopes are eyeglasses which contain miniature telescopes. They are like miniature binoculars mounted onto eyeglasses. They can help individuals who have a visual impairment (low vision) see more clearly for a full range of visual activities– to help them see better far away, at midrange and even close-up.
There are two types of bioptic telescope optical designs--Galilean and Keplerian
Galilean telescopes are smaller and lighter weight and are great at 1.7x and 2.2x powers, but their fields of view become very narrow at powers of 3x and higher. So, when prescribing powers of 3x and higher, Keplerian telescopes, which have a more complicated optical design which includes both lenses and prisms, will provide much wider fields of view that users prefer. All bioptic telescopes can be used both for distance and near seeing distances. Galilean telescopes are available as manual focusable or fixed focus devices that use ‘reading caps’ to be focused at near distances. Keplerian telescopes are available as both manual focus and autofocus versions.