A closer look at safety glasses
Thousands of eye injuries occur on jobsites every day, and many of them could have been prevented with the proper safety glasses. There are a few different types of lenses available in safety glasses, and knowing the properties of each material will help you choose the best protection.
Plastic lenses for safety glasses
Lighter and more comfortable than glass, plastic lenses need to be thick enough to meet industry impact resistance standards. Plastic lenses will scratch, but they are more scratch resistant than polycarbonate and typically more durable. If you will be wearing plastic safety glasses outside, make sure they’ve been treated with an adequate UV coating to protect your vision from the sun (just because they are tinted does not necessarily mean they protect from UV rays).
Polycarbonate is popular
Because polycarbonate offers the best impact resistance, it is the most popular option for both prescription and non-prescription safety eyewear. The material is a bit softer than plastic and much softer than glass, so it absorbs energy without breaking. Polycarbonate lenses offer close to 100 percent UV protection, but must be coated to offer scratch resistance. This is the preferred material for most personal protective equipment experts, and they recommend rinsing with clean water and wiping them dry every day to prevent the build up of static electricity.
Glass offers the clearest view
Once the most popular option in safety eyewear, demand is decreasing due to the expense. Glass is still the most popular option for prescription safety glasses, as they offer the best optical quality. To meet impact resistance standards, glass safety glasses must be tempered in a chemical bath, and many experts still recommend other lens types when impact injuries are a concern. In workplaces where static electricity could pose a problem (millwork shops with a lot of fine airborne dust, for instance) glass lenses are often the best choice.
—By Roberto Franco