Spectacle optics.
Do we have an optician amongst us who can answer the question posed here.
It involves the optician's definition of ADD. Is that strictly a mathematical one
or does it mean something else?
Here is the question:
The following is a bi-focal prescription for glasses.
1 and 2 are for the right and left eyes respectively.
1). . . . . . . Sph. . . . Cyl. . . Axis
Distance -2.5 . . . -2.75 . . . 100
Near. . . . +0.75 . . . -2.75 . . .100
2). . . . . . . Sph. . . . Cyl. . . . Axis
Distance -0.25 . . . -150 . . . 90
Near. . . +3.00 . . . -150 . . .90
Question:
If only a pair of reading glasses are required.
What figures are to be used?
Would these be the correct ones?
1R). . . . . Sph. . . . Cyl. . . ' Axis
Near. . . . -1.75 . . . -5.50 . . . 100
2R). . . . . Sph. . . . Cyl. . . . Axis
Near. . . +2.75 . . . -300 . . . 90
No guesses please. Or alternative approaches.
Just a correct answer.
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