Reading Strength
Ready made reading glasses (off the shelf) include only the Sphere correction component in the lens.
Prescription reading glasses include both Sphere and Cylinder-Axis correction components in the lenses, shown below.
| R eye: | Sph: +1.25, | Cyl: -1.00, | Axis: 70 |
| L eye: | Sph: +1.75, | Cyl: -1.25, | Axis: 25 |
To obtain your strength for ready made reading glasses, use the prescription format examples below.
Prescription 1
| Sph | Cyl | Axis | Sph | Cyl | Axis | |||
|---|---|---|---|---|---|---|---|---|
| R | -1.25 | -1.00 | 70 | Distance | -0.75 | -1.25 | 25 | L |
| +1.25 | -1.00 | 70 | Near | +1.75 | -1.25 | 25 |
Prescription 1 shows the single vision reading glasses requirement in the 'Near' row.
| R eye: | Sph | +1.25 |
| L eye: | Sph | +1.75 |
Prescription 2
| Sph | Cyl | Axis | Sph | Cyl | Axis | |||
|---|---|---|---|---|---|---|---|---|
| R | -1.25 | -1.00 | 70 | Distance | -0.75 | -1.25 | 25 | L |
| +2.50 Add | Near | +2.50 Add | ||||||
Prescription 2 is for bifocal or varifocal glasses, the reading strengths are:
| R eye: | Sph | + | Near Add | = | -1.25 +2.50 = +1.25 |
| L eye: | Sph | + | Near Add | = | -0.75 +2.50 = +1.75 |
Prescription 3
| Sph | Cyl | Axis | Near Add | |
|---|---|---|---|---|
| R | -1.25 | -1.00 | 70 | +2.50 |
| L | -0.75 | -1.25 | 25 | +2.50 |
Prescription 3 is a reformatted version of Prescription 2.
| R eye: | Sph | + | Near Add | = | -1.25 +2.50 = +1.25 |
| L eye: | Sph | + | Near Add | = | -0.75 +2.50 = +1.75 |