- 1). Test yourself with an eye chart. Eye charts can be found in drugstores or anywhere pre-made reading glasses are sold. Eye charts can also be found online. Typically, eye charts present a series of letters or a sentence in varying sizes next to a number representing a prescription strength. Whichever line is most easily read will determine the required strength of reading glasses.
- 2). Determine the strength of the glasses based on age. Individuals in their early 40s typically require reading glasses with a strength of +1.25, while individuals in their late 40's need a strength of +1.75. For individuals in their 50s and older, typically glasses strength should be +2.25 or higher.
- 3). Consult a pharmacist. Many drugstores have pre-made reading glasses in a variety of strengths, and pharmacists can assist in picking out the correct strength. Pre-made glasses are cheaper than prescription glasses, and pharmacists' help is free. Pre-made reading glasses can also often be purchased in bookstores or grocery stores.
- 4). Visit an optometrist. The most accurate prescription comes from a doctor. Optometrists have tests to determine the required strength of reading glasses, and prescribe glasses. This is especially important, according to optometrists, if different strengths are needed for each eye.
Source...