Binocular reading additions from + 4.00 D to + 14.00 D were prescribed to 120 patients. Fifty percent of corrections were prescribed for patients with macular degeneration and cataracts, and nearly 25% to patients with heredo-degeneration of the macula. Sixty percent of corrections were prescribed for vision ranging from 20/200 to 20/ 100. Ninety-two percent of corrections were prescribed in the form of bifocals or half-eye glasses. Bifocals make the most inconspicuous optical aid and are indicated when there is a significant distant correction. Half-eye glasses were prescribed for 64%. These are ideal because the lenses can be made small. Bifocal segments must be decentered in 1 mm for each diopter of reading addition for each eye, or 1Δ of base-in prism must be incorporated for each diopter of reading addition for each eye. Eighty-eight percent were judged successful.
Fonda G. Binocular Reading Additions for Low VisionReport of 120 Cases. Arch Ophthalmol. 1970;83(3):294-299. doi:10.1001/archopht.1970.00990030296005