title: Spectacles for the emmetropic presbyopic optometrist.
abstract: Presbyopia brings special seeing problems for an emmetropic optometrist. Incorporating the bifocal into a half-glass offers several advantages. The best parameters for this spectacle form are derived from experience, and also by comparing it to single-vision half-glasses, bifocals, and trifocals. Particular facility in both prescribing and fabricating derives from the great number of power and size relations between upper and lower segments available. One can extrapolate similar benefits in this spectacle form for other occupations and hobbies as well as for presbyopic wearers of single-vision contact lenses.
mesh_terms: D000488:Allied Health Personnel; D005139:Eyeglasses / Q000592:standards*; D006801:Humans; D009907:Optometry; D011305:Presbyopia / Q000628:therapy*