OPTOM 10 Lecture Notes - Lecture 3: Oxygen Permeability, Gel, Water Content
Document Summary
Problems: they were made with blown glass, hard to customize, it also transmits no oxygen to go through glass, they made about 2,000 lenses (usually low prescriptions, less than. Instead of glass, make it out of pmma: ppl can customize and shape the lens the way you want, lathe: a cutting device which the object being cut is spinning. Peripheral curves: edge of the peripheral curves flatten out a bit. 1950s and 60s: made small lenses to help with less edema, more tear exchange, made it thinner to be more comfortable, put holes in the lenses to get tears flowing through the lens to improve o2 delivery. O2 as open eye therefore a little bit of swelling: cornea swells 2-3% overnight. Lathe-cut: if dries out, becomes brittle, they would lathe cut it and then hydrate it, then becomes gel, flexible soft material, can control the shape that you"re making, very few are lathe-cut nowadays, modern is cast-molded.
