Granny glasses are glasses with small lenses which may be round or rectangular, depending on style. They were popularized by the counterculture movement of the 1960s, when granny glasses were seem on people like John Lennon and other leaders of the hippie movement. People who embrace the hippie lifestyle sometimes choose to wear granny glasses, and of course these small glasses are also worn by older people, who use the lenses for reading and other tasks.

The shape of granny glasses can vary. Many people during the 1960s sported granny glasses with rectangular lenses and thin frames or half-frames. The lenses in these granny glasses would have been small, with people who actually need glasses for vision correction using this style for reading and detail work, rather than donning such glasses for general wear. Another common style of granny glasses uses round lenses in full or half frames.

Round granny glasses are sometimes referred to as Ben Franklin glasses, referencing the famous inventor who created the round lens style for vision correction. Several portraits of Ben Franklin show him sporting his own set of glasses with their distinctively round, small lenses and lightweight frame. The lightweight, small glasses are ideally suited to intermittent wear, with people donning such glasses to read or work on projects with challenging visual detail. This is why many people associate such glasses with older people like grandmothers, as older people often need vision correction for certain kinds of tasks.

Granny glasses can be fitted with prescription lenses, although the small lens size makes them less than ideal for casual wear. Many people in the 1960s chose to wear granny glasses with tinted lenses, using them as sunglasses, and the tinting was sometimes done in an unusual color like pink or orange. Some people combined granny glasses with another fad of the 1960s, glassless glasses, wearing simply the frames, with no lenses installed.

Interest in granny glasses faded quickly in the 1960s, as often happens within fads. Within a few years of becoming trendy, the glasses essentially vanished overnight, with people adopting new styles. However, granny glasses have become so closely associated with the hippie era that they are often worn by people dressing up as hippies, or by people who wish to identify with this period in history.