state the surface powers required to produce the following lenses with +6.25D front curves.
a. -0.50 DS
6. +0.50 DS
c. +1.75 DS
Did you ever figure it out?? I am doing something VERY similar now
To calculate the surface powers required to produce a lens with a specific front curve, we can use the lens formula:
Surface Power = Front Curve - Back Curve.
In this case, the front curve is +6.25D, and we need to calculate the surface power for each given prescription. Here's how you can do it:
a. For a lens with -0.50 DS prescription:
Surface Power = Front Curve - Back Curve
Front Curve = +6.25D
Back Curve = -0.50D
Surface Power = +6.25D - (-0.50D)
Surface Power = +6.25D + 0.50D
Surface Power = +6.75D
Therefore, the surface power required for a lens with a front curve of +6.25D and a -0.50 DS prescription is +6.75D.
b. For a lens with +0.50 DS prescription:
Surface Power = Front Curve - Back Curve
Front Curve = +6.25D
Back Curve = +0.50D
Surface Power = +6.25D - (+0.50D)
Surface Power = +6.25D - 0.50D
Surface Power = +5.75D
Therefore, the surface power required for a lens with a front curve of +6.25D and a +0.50 DS prescription is +5.75D.
c. For a lens with +1.75 DS prescription:
Surface Power = Front Curve - Back Curve
Front Curve = +6.25D
Back Curve = +1.75D
Surface Power = +6.25D - (+1.75D)
Surface Power = +6.25D - 1.75D
Surface Power = +4.50D
Therefore, the surface power required for a lens with a front curve of +6.25D and a +1.75 DS prescription is +4.50D.