The construction eye-protection rule was rewritten in 2016 to mirror the general-industry version, so the triggers are now the same on both sides of the line.
The trigger. The employer must ensure each affected employee uses appropriate eye or face protection when exposed to eye or face hazards from flying particles, molten metal, liquid chemicals, acids or caustic liquids, chemical gases or vapors, or potentially injurious light radiation (29 CFR 1926.102(a)(1)). Grinding, chipping, cutting, nailing with powder-actuated tools, mixing concrete additives, and welding each land on that list.
Side protection, prescriptions and marking. When the hazard is flying objects, eye protection must provide side protection; detachable side shields that meet the standard are acceptable (29 CFR 1926.102(a)(2)). Employees who wear prescription lenses in operations with eye hazards must wear protection that incorporates the prescription or that can be worn over the prescription lenses without disturbing the position of either (29 CFR 1926.102(a)(3)). Eye and face PPE must be distinctly marked to identify the manufacturer (29 CFR 1926.102(a)(4)).
What counts. Protective devices must comply with one of the consensus standards listed in paragraph (b)(1) — the ANSI/ISEA Z87.1 editions incorporated by reference — or be demonstrated to be equally effective (29 CFR 1926.102(b)(1)). In practice, "Z87" stamped on the frame is how a competent person checks.
Ordinary prescription glasses are the most common failure: they are not safety glasses, and the standard addresses them by name.