ANSI Z87+ vs. Z87.1: What’s the Difference and Which Safety Glasses Do You Need?

If you’ve ever worn safety frames, you’ve likely seen “Z87” stamped on the frame. When it comes to eye protection, that small plus sign in “Z87+” makes a big difference in how much protection the frames provide.

If you’re wondering which stamp you actually need — ANSI Z87+ vs. Z87.1 — allow us first to address the core confusion. ANSI Z87.1 is the name of the safety standard, while the plus (+) symbol indicates that the frames have passed the standard’s high-impact testing requirements. 

The distinction is essential, depending on your line of work. Glasses marked with the basic “ANSI Z87” stamp don’t provide the same protection as those bearing the ANSI Z87+ high-impact rating. Wearing safety glasses rated for basic impacts only in a high-impact environment leaves you vulnerable to severe workplace eye injuries and noncompliance fines. 

To help you prevent both, Rx-Safety carries a comprehensive line of custom prescription safety eyewear certified to meet exact ANSI standards for various applications. Before you browse, we’ll explain how to read safety glass markings and what they mean.

WHAT IS THE ANSI Z87.1 STANDARD?

The first standard in the United States for eye and head protection dates  back to 1922. In 1968, the American National Standards Institute (ANSI) published the standard that forms the foundation of the current version, Z87.1-1968. 

Over the years, the standard has seen several revisions. Early in the 21st century, the International Safety Equipment Association (ISEA) became involved with the publication of ANSI/ISEA Z87.1-2003. Since 2003, ISEA and ANSI have maintained and updated the standard, with the latest revision published in 2025.

The current standard, ANSI/ISEA Z87.1-2025, establishes strict protocols for the design, construction, testing, and use of eye and face protection, including safety glasses, goggles, face shields, and welding helmets, to protect against hazards like impact, liquid splash, dust, and radiation.

Under ANSI Z87.1 safety standards, eye, face, and head protection must meet stringent performance requirements to receive certification.

Optical and Material Requirements

• Optical clarity: Lenses must have minimal distortion, accurate light transmission, and low haze (≤ 3%) to prevent eye strain.
• Coverage area: Frame designs must provide the specified minimum lateral (side) and vertical physical protection zones.
• Ignition resistance: Components must not glow or catch fire after 5 seconds of direct contact with a rod heated to 650°C (1202°F).

Environmental and Hazard Protection

• Liquid splash: Technicians test the frames’ droplet and splash protection using specialized liquid exposure.
• Dust and fine dust: Tests evaluate barrier effectiveness against coarse particles, such as metal shavings or sawdust, and fine powders, such as dust or fine wood particles.

Structural Integrity

Technicians assess a pair of glasses for structural integrity by subjecting them to several impact tests, resulting in a pass-or-fail determination. These tests assess the lenses and frames simultaneously. 

A piece of eyewear fails the structural integrity component of an impact test if any of these outcomes occur:

• Lens dislodgement: The frame fails to hold the lens, which pops out of the groove.
• Component detachment: The temples, nose pieces, or side shields break away from the frames.
• Fracture: The frame, lens, or housing cracks, breaks, or shatters.
• Contact with headform: The frame or lens warps, buckles, or collapses inward enough to touch the test headform’s eye or face area.

By evaluating structural integrity during impact testing, technicians confirm that the frames and lenses function as a unified system. A strong lens is useless if the frame snaps upon impact, and a rugged frame is ineffective if it cannot retain the lens.

THE CORE DIFFERENCE: BASIC IMPACT (Z87) VS. HIGH IMPACT (Z87+)

Safety glasses must pass multiple tests to receive ANSI Z87+ vs. Z87.1 certification. These tests determine whether a pair of safety glasses will remain intact through a series of punishing impacts. 

We’ll break down the differences between basic impact (Z87) and high impact (Z87+) ratings.

HOW TO FIND AND READ THE STAMPED MARKINGS ON YOUR GLASSES

Generally, you’ll find safety certifications stamped or etched on the inside of the temple arms near the earpieces, on the front of the frames, or at the top outer edge or corner of either lens. The manufacturer’s logo or trademark symbol usually appears first, followed by the rating code.

In addition to the Z87, Z87+, Z87-2, or Z87-2+ impact ratings, you may see other codes, each indicating another type of protection the safety glasses provide.

THE BOTTOM LINE ON ANSI Z87+ VS. Z87.1 SAFETY GLASSES

When it comes to eye protection, you shouldn’t have to guess. Always verify your workplace requirements before buying, and match the safety ratings to your specific application. 

Browse Rx-Safety’s catalog of ANSI Z87+ high-impact certified prescription safety glasses and customize your lenses today.