Your reading glasses lens strength is determined by your age, your reading distance and if you wear or need prescription eyeglasses for other distances.

Estimate Your Reading Glasses Strength

Since age is the main determining factor in the onset of presbyopia, having trouble seeing things close-up, use the timeline below as a starting point to finding your reading glasses lens power.


As you move your reading glasses down your nose, the magnification increases. So if you like to position your readers low on your nose so you can read and watch TV, adjust the lens power you choose slightly.

  • 30-40 years old start with +1.00
  • 45 years old +1.50
  • 50 years old +2.00
  • 60 years old +2.50 - +3.00

Determine Your Reading Distance

Print out our Eye Chart to help you find the correct lens power for you.

-Traditional book reading distance is 14-16 inches

-Computer reading distance is 18-20 inches.

Fact: 01:

scientific principle: focal power is inversely related to focal length


If you want to use your reading glasses at your computer - first, find the correct lens power at traditional reading distance. Then reduce that lens strength by about half. This may need tweaking depending on the distance of your computer screen to your eyes.


You Have a Doctor’s Prescription

If you do have a prescription from an eye care professional, ask them whether non-prescription reading glasses are right for you and if so, what lens strength they would recommend. If most of your reading is done at the computer then measure your specific computer reading distance (from your eyes to the monitor) and bring this to the attention of your doctor so that you get a correction that will work best for you.

Print Chart


Computer resolution differences require this chart be printed for accurate results. Actual sizing may vary depending on your computer settings.


First, read at traditional reading distance of 14-16 inches. The first line you have difficulty reading is your suggested lens strength at that distance. For computer reading reduce that strength by about half. Adjust to your liking.


Still not sure what’s your best reading glasses lens strength? Our Licensed optician is available to help you. Just email us:

Just A Few More Things


Reading Distances:

Working at a computer screen at 18” away will require a different lens power than working at one that is 28” away or working on your laptop, reading a book on your lap or reading papers on your desk. Choosing a designated lens power for each reading distance will eliminate eyestrain. Many times different corrections are needed for different distances.

Wearing Distance:

Some people like to wear their readers down their nose so they can easily look over them in the distance and also read up close, like when watching T.V. while reading a newspaper or iPad. If this sounds like you, choose reading glasses with extra-long temples so they stay on securely and a smaller lens depth so you can look over them easily.