Lens Power (Diopter)

What diopter (or lens power) monocle is right for me?
The best way to determine your needed visual correction is to visit your optometrist.  He or she will be able to check your vision and provide an accurate assessment of your needs.

If you already wear reading glasses, then choose a monocle that is the same diopter as your current reading glasses, rounding up to the nearest 0.50 diopter.  For example: if your reading glasses are +1.25, get a monocle that is +1.50.  If your reading glasses are +2.75, then get a monocle that is +3.00.

Finally, you can also use our Home Eye Test to test your vision to approximate your needed vision correction:

  1. Click here to download the Nearsights Home Eye Test
  2. Print out the test and follow the on-page instructions
  3. Order your monocle and enjoy!
Do you sell +1.25 or +1.75 diopter monocles?  What about other +0.25 increments?
Unfortunately we only offer our monocles in diopter increments of +0.5.  However, the difference between a +1.25 lens and a +1.50 (or +1.75 and +2.00) diopter lens is quite small.  We recommend "rounding up" to the nearest +0.50 diopter.

And - if you absolutely must have a +1.25 (or other +.25 increment) lens, then we will be happy to create a custom Prescription Monocle to meet your needs.

What is diopter?

Diopter is a term used to identify the refractive (light bending) capacity of a lens.  A higher diopter indicates a higher refractive capacity, and a greater magnification.

Diopter Magnification
Focal Length (cm) Focal Length (in)
0.0 (No magnification) 1.00 X (Actual size)
0.5 1.13 X 200 79
1.0 1.25 X 100 39
1.5 1.38 X 67 26
2.0 1.50 X 50 20
2.5 1.63 X 40 16
3.0 1.75 X 33 13
3.5 1.88 X 29 11
4.0 2.00 X 25 10

You can learn more about diopter on Wikipedia.