optical RX explained?

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optical RX explained?

does a larger negative number under "SPH" or "CYL" indicate a stronger lens?

2007-07-04 04:07:44 · 2 answers · asked by silentnonrev 7 in Science & Mathematics ➔ Medicine

2 answers

A stronger in the sense a more curved lens. - indicates that it is a concave lens. + indicates a convex lens.

That number is called Dioptre and is 1/focal length of the lens expressed in meters. Thus + 1 indicates a focal length of 1m, +2 indicates a focal length of 0.5 m and so on.

2007-07-04 05:04:58 · answer #1 · answered by Swamy 7 · 0⤊ 0⤋

Yes, that's the power of the lens. If you are above -5 you are getting into coke bottle glasses unless you go high index.

2007-07-04 11:11:50 · answer #2 · answered by RP McMurphy 4 · 0⤊ 0⤋