2007-03-28 14:47:37 · 3 answers · asked by BL 5 in Health ➔ General Health Care ➔ Other - General Health Care
if you look at a pair of glasses you will see a line across the bottom when they are a bifocal. A progressive no line bifocal has no line it is more like a trifocals because the prescription gradually switches to the bifocal. the in between script is like for computers and things at about that level away from your eyes.
2007-03-28 16:18:26 · answer #1 · answered by mamaac43 3 · 0⤊ 0⤋
In bi-focal or tri-focal lenses, there is a definite line of demarcation, between each of the prescriptions. In progressive, they meld into one from the other without any lines.
2007-03-28 14:56:39 · answer #2 · answered by Beau R 7 · 0⤊ 0⤋
bi-focal is 2 different prescriptions in different spots
progressive is different prescriptions that "blend" together (no line)
2007-03-28 14:51:35 · answer #3 · answered by Anonymous · 0⤊ 0⤋