Eye Prescription to 20/20 Scale
Enter your prescription values to estimate Snellen visual acuity.
Sphere (D)
Please enter a valid sphere value between -20 and 20.
Negative for myopia, positive for hyperopia.
Cylinder (D)
Please enter a valid cylinder value between -10 and 10.
Usually negative. Zero if no astigmatism.
Axis (°)
Axis must be between 0 and 180.
Required only if cylinder is non-zero.
Age
Age must be between 1 and 120.
Calculate 20/20 Equivalent
Estimated Snellen Visual Acuity
How it's calculated