What is my vision as a fraction?

Question

In my left eye, my prescription is -3.00 and in my right eye my prescription is -3.25. That's what it says on my box of contacts.

Answer 1

To determine your visual acuity you must read an eye chart.

Answer 2

20/20 isn't perfect vision, it is "normal" vision. It can be better than 20/20...20/15 is better....20/10 is better still

The 20/XX number is your visual acuity.

You most likely have 20/20 WITH your contacts on.

Without any corrective lenses, presuming you have straight simple myopia, you vision would be in the 20/300 range.

It's pure coincidence that at - 3.00 to - -4.00 , the power is about equal to the 20/20 value.

This is just an approximation , because other variables can affect the visual acuity. The only way to be real sure is to see the actual results from the chart measurements the Dr. did.

The visual acuity reading from the chart doesn't determine the prescription needed, and the prescription doesn't really determine what the visual acuity is. Those are 2 different things.