What are the major signs of laser injury to the eyes if laser safety glasses aren't used?

Many different symptoms can be associated with laser injury to eyes, unfortunately it is often not until significant damage occurs that the individual realizes the problem. For different laser wavelengths, the damage will be slightly different. There are few pain receptors within the eye and the retina, so laser damage may not be easily noticed. Problems and symptoms of laser energy exposure are usually caused by either not having glasses, or wearing the incorrect glasses. One common problem is experiencing bright color flashes when exposed to a visible light beam. The color flash will correspond to the particular wavelength that caused the damage. With retinal damage the ability to distinguish between green and blue colors may become increasingly problematic and the retina may develop spots of pigmentation, leading to vision problems. Certain types of laser systems, including the YAG systems, can produce serious long term retinal damage known as visual disorientation. Occasionally, a sound that resembles a loud pop is heard when the damage occurs, but may not be associated with a vision problem until later when subsequent exposure worsens the problem.

What is the most popular style of laser safety glasses and why?

The most popular style of laser safety glasses in most labs are the wrap around style, usually because they are lightweight, fits any adult sized head, and are also very comfortable to wear. Wrap around styles provide good side shielding and are similar to popular styles of sunglasses, so they look less like traditional laser safety glasses. Other popular styles include the aviator styles, which have a larger lens area and provide a very clear field of vision. The selection of the style of glasses used in your facility is a personal choice. However, keep in mind that the more comfortable the frames are, the more likely all employees will be in wearing their glasses as required.

Can I tell what type of lenses are in laser safety glasses by the color of the lens itself?

No. There is no way to tell what specific wavelength and optical density that laser safety glasses are designed for just by the lens color alone. This is because there are only very slight variations in many of the lens colors, and they are virtually undetectable to the human eye. In addition some lens colors are the same but are designed for different wavelengths. It is therefore important to do some additional coding or identifying of the laser safety glasses based on the specification of the laser system they were ordered for use with. It is a good idea to begin a color coding system or a number system that associates one type of lens and glass with a specific laser system. This way employees, technicians and others who work in the facility don't assume thatall amber lenses can be used with a particular laser system, or that all red lenses are acceptable with another.