Laser safety starts with knowledge. Without it, blindness can happen in the blink of an eye. Lasers span distances at the speed of light, which, according to physics, is the fastest speed possible. There will be no warning before a laser beam does its damage. One instant, you are fine, and the next, you aren't.

Besides their near instantaneous speed, laser light is collimated. That is, their rays of light are nearly parallel. This means the energy intensity of a beam diminishes little with distance. Depending on the laser, its beam may spread out by only a tenth of an inch after traveling ten feet.

This is quite different from ordinary light, which diminishes in intensity with the square of its distance. For example, its intensity diminishes …show more content…
Lasers in the class 1 & 2 categories are generally considered safe, unless you deliberately stare into the beam for lengthy periods. This is especially true of class 2, which is safe if your blink reflex causes you to look away. Class 3B & 4 lasers will damage the eye and potentially cause blindness if the laser's wavelength allows it to penetrate past your cornea and lens. Visible light and short wavelength infrared do this.

In terms of laser safety, the above facts mean that your eye health hinges on knowledge and the willingness to act on it so that you never make that one mistake that could cost you your vision. Here are seven frequently asked questions and answers about laser safety and laser safety glasses that might save your vision:

When Should I Wear Laser Safety …show more content…
Inability to see a beam does not mean you are safe from laser exposure. The laser beam may be hidden from your line of sight. Changing your position may expose you to the beam or a reflection. In addition, some lasers are invisible, such as ultraviolet and infrared. Always follow established safety protocol about when to wear laser eye protection and when it is safe to remove them.

What Are the Signs of Worn or Damaged Laser Safety Eyewear?

Look for signs of lens damage such as scratches, cracks, discoloration, gouges, or holes. Never wear laser safety glasses with damaged frames or straps, even if the lenses are in good condition. You can not count on them to reliably hold the lenses in place.

If the wavelength and optical density labeling on the glasses is worn off or is otherwise missing, replace the labeling or discard the glasses. Even if you know this information, someone else won't and may use the glasses with lasers that they won't protect against. Of course, one should never use laser safety eyewear without knowing the type of laser light it's supposed to filter out.

Will Laser Safety Glasses Protect Against