My eyes are -3.75 where does that sit with the 20/20 scale? Would I be ?/20 or 20/?

Question

How can I figure my exact number knowing my prescription?

Answer 1

Geoffrey is very confused.

We can't tell exactly what your visual acuity  ( 20/20 value )is just by seeing the prescription.

That is a complete different measurement and has several variables that can affect it.

But...if you have simple myopia with no astigmatism or any other eye condition, you would be in the 20/400 range with no correction .

Which means that you have to be 20 feet from an object to see it as clear as a normal eye would see at 400 feet.

But you are most likely 20/20 with your glasses or contacts on....which means you see at 20 feet what a normal eye should see at 20 feet.

Answer 2

17.25/20, subtract your weak eye power number from 20.