Contact Lens Power Conversion Chart (Glasses to Contacts)
Your glasses sit about 12 mm in front of your eyes; contact lenses sit directly on them. That distance (the vertex distance) changes the effective power — so for stronger prescriptions, your contact lens power is not the same as your glasses power. This chart does the conversion.
The rule in one line
Glasses power -4.00 or weaker: no change needed. Order the same power as your glasses. Stronger than -4.00: use the chart below.
Conversion chart (myopia / minus powers)
| Glasses prescription | Contact lens power to order |
|---|---|
| 0.00 to -4.00 | Same as glasses — no adjustment |
| -4.25 | -4.00 |
| -4.50 | -4.25 |
| -5.00 | -4.75 |
| -5.50 | -5.25 |
| -6.00 | -5.50 |
| -6.50 | -6.00 |
| -7.00 | -6.50 |
| -7.50 | -7.00 |
| -8.00 | -7.25 |
| -9.00 | -8.00 |
| -10.00 | -9.00 |
Worked example
Your glasses say OD (right) -5.00, OS (left) -4.25. From the chart: order -4.75 for the right eye and -4.00 for the left. On any Mojosee product page, pick each eye's power separately in the POWER selector.
Three things this chart cannot do
- Astigmatism (CYL/AXIS): if your prescription has significant cylinder values, spherical colored lenses may not fully correct you — ask your eye-care professional about spherical equivalent.
- Plus powers (farsighted): the adjustment goes the other direction; confirm with your optometrist.
- Replace an eye exam: this is a standard optical vertex conversion, not medical advice. Base curve and fit still need a professional fitting — see our safety guide.
Ready to order? Browse colored contacts for dark eyes — most designs carry powers from 0.00 (plano) to -8.00.
