4.1.2

Question 1

What is focimetry tolerances for sphere

Answer 1

Sphere up to 6.5D = tolerance up to 0.12D
Sphere > 6.5D = tolerance is 2% of sph value

Question 2

What is focimetry tolerances for cyl

Answer 2

Cyl up to 2D = tolerance is up to 0.12D
Cyl 2D-4.5D = tolerance is up to 0.18D
Cyl > 4.5D = tolerance is 4% of cyl value

Question 3

What is focimetry tolerances for axis

Answer 3

0.25D-0.5D = 7 degrees
0.5D-0.75D = 5 degrees
0.75D-1.50D = 3 degrees
>1.5D = 2 degrees

Question 4

What is focimetry tolerances for ADD power

Answer 4

Up to +4.00D = up to 0.12D
> +4.00D = up to 0.18D

Manual focimeters can go up in 0.12 steps