How can eye doctors determine the right prescription?

Thos is very .... Subjective, you respond to the doctor when using different lenses San asks which is best or clearest number one or number two.

Related Questions

How do eye doctors determine the right prescription for both eyes if they are different?

The 1-2 test. This test where the eye doctor asks which is better number 1 or number 2. This is called a manifest refraction , it is very subjective. You tell the doctor which you see clearest, then writes your prescription. Read more...