Safety Glasses Buying Guide — ANSI Ratings and Lens Materials
Regular glasses are not safety glasses. In a workshop, lab, or construction site, standard lenses can shatter on impact, sending sharp fragments into your eyes. Here is what to look for in genuine protective eyewear.
ANSI Z87.1 — The Standard That Matters
In the United States, safety glasses must meet ANSI Z87.1 standards. Look for the Z87+ marking on the frame or lens — this means the glasses passed high-velocity impact testing (a quarter-inch steel ball fired at 150 feet per second). Without this mark, it is not safety-rated, regardless of what the marketing says.
Lens Materials for Safety Glasses
- Polycarbonate: The industry standard. 10x more impact-resistant than standard plastic (CR-39). Built-in UV protection. Used in 90% of safety glasses. Thinner and lighter than Trivex.
- Trivex: Similar impact resistance to polycarbonate but with better optical clarity (less chromatic aberration). Lighter weight. More expensive. Preferred by labs and precision work environments.
- Glass (tempered): Highly scratch-resistant but heavy and can still shatter. Rarely used today except in extreme chemical environments where plastics would degrade.
Prescription Safety Glasses
If you need prescription lenses, you have two options:
1. Prescription safety glasses: Custom-made with your Rx in Z87-rated frames. Available from online retailers like RX Safety and Safety Gear Pro starting around $60.
2. Over-the-glasses (OTG) safety glasses: Wear over your regular prescription glasses. Cheaper ($10-20) but bulkier and less comfortable for all-day wear.
Coatings Worth Paying For
- Anti-fog: Essential if you wear a mask, work in humid environments, or move between hot and cold areas
- Anti-scratch: Polycarbonate is softer than glass and scratches more easily — this coating extends lens life significantly
- UV protection: Standard on polycarbonate, but verify if buying other materials