If I have 20/70 vision what is the power of the lenses needed to correct my vision (how do I calculate it?)
To calculate the power of lenses needed to correct your vision, you can use the formula:
Lens Power = (1 / Vision) * 10
In your case, if you have 20/70 vision, you would plug in the value of your vision into the formula:
Lens Power = (1 / 70) * 10
Now, let's calculate it:
Lens Power = 0.0143 * 10
Lens Power = 0.143
So, the power of the lenses needed to correct your vision would be approximately +0.14 diopters. The positive sign indicates that your lenses would be converging lenses (commonly known as convex lenses) used for correcting farsightedness or hyperopia.