Eyewear: Safety

What features should safety eyewear include?
How should safety eyewear lenses be crafted?

What features should safety eyewear include?

In addition to correcting vision, eyewear can help protect the eyes. Here are some general guidelines to consider when selecting safety eyewear frames:

Consider frames with side shields, which protect against objects coming at the eyes from an angle, as well as from the front.
The frames should be made of impact-resistant plastic or polycarbonate.
For cold weather wear, look for frames made of nylon, rubber or propionate, which do not become brittle in the cold, hold their shape, and are less likely to injure the face in a fall or when something strikes them.
Titanium is an unusually tough metal used in some sports eyeglasses.
Wrap-around temples keep the frame more firmly in place.
Spring hinges allow the frame to flex without breaking.

How should safety eyewear lenses be crafted?

As for the lenses, safety eyeglasses can be prescription or nonprescription. They can be made of extra-thick glass or plastic. A commonly used plastic is polycarbonate, which offers the same kind of impact resistance in lenses as it does in frames.

One aspect of the eye protection that glasses can offer, and that often is overlooked, is protection against ultraviolet light, which can cause eye damage as well as sunburn. Plastic lenses can be treated with a special dye that will prevent ultraviolet light from reaching the eye. Lenses that screen out both the ultraviolet-A and ultraviolet-B wavelengths in sunlight offer the best protection. The label will indicate that the sunglasses screen both ultraviolet-A and ultraviolet-B, or the label may say that sunglasses screen light "below 400 nm," or nanometers, the wavelengths of ultraviolet light.

For night driving, lenses can be treated with antireflective coatings that reduce glare -- something that can be of major importance with a person who has early cataracts or another condition that makes glare a problem.

Eyewear can be customized for protection against eyestrain. An eyeglass wearer who spends hours in front of a computer screen can choose special bifocal lenses for looking down at the keyboard or up at the monitor. A person who looks up at work constantly can get bifocals with near-distance segments at both the top and bottom of the lenses.

Although a good fit is important for all eyewear, it is especially recommended for safety eyeglasses.