Strengths of Reading Glasses

The elasticity of the lens in your eyes deteriorates as you age. This loss of flexibility, or presbyopia, results in difficulty focusing and an inability to read things at a close distance. Presbyopia can be countered with reading glasses, either purchased inexpensively at a drugstore or through a prescription from your eye doctor. Over-the-counter reading glasses come in several basic strengths and are an easy solution for many people.

Choosing Drugstore Reading Glasses

• Determining the strength of drugstore reading glasses required is simple. Charts are available at the drugstore eye counter or online. To use an online chart, print it out and hold it at the distance you normally hold reading material. Attempt to read each line. Read the chart from top to bottom. Each line has a magnification strength listed next to it, ranging from +1.00 to +3.25 in increments of .25. The first line you have difficulty reading will determine the strength of magnification you require in a pair of reading glasses.

When You Need Prescription Reading Glasses

• Drugstore reading glasses will have the same magnification in each lens. This may not work if you have very different levels of presbyopia in each eye; use of drugstore reading glasses will give you a headache or eye strain. Prescription lenses also have the benefit of having the lens' optical center customized to your eye. Prescription reading glasses are available in half-frame styles, ideal for people who do not wear glasses otherwise and only need to use the reading glasses occasionally, or full-frame styles, meant for people who spend most of their time reading or looking at objects close up.

Reading Glasses For Those With Other Vision Problems

• If you already wear corrective glasses for another eye problem, you can also use reading glasses. Prescription bifocals or progressive lenses (which do not have the tell-tale line of traditional bifocals) combine your reading glass prescription with your regular prescription so you can read by looking down through your glasses and see otherwise by looking up.