Spiral Focusable Galilean Bioptics
The Spiral (focusable) Galilian bioptics were designed by Designs for Vision, the company founded by William Fienbloom in 1961. These Galilian telescopic systems can focus from 12inches to distance (infinity). The 3X and 4X are available in the bioptic form that can be used for bioptic driving. The 3X systems presents with 8 degrees of visual field and the 4X telescopes presents with 6 degrees of visual field. They can be fit as a binocular or monocular system. Slip-in sunglasses can be adapted to fit behind the lenses. The focus is set to distance for driving. Optical infinity is anything farther than 20 feet. So the patient sets the focus on an object past 20 feet and leaves the focus alone while driving.