Unprotected, extended exposure to which of the following can cause cataracts?

• A. Visible light
• B. Ultraviolet light
• C. Infrared light
• D. X-rays

Answer: (C)

Infrared radiation from welding arcs carries heat that can warm the eye’s lens. When exposure is prolonged and unprotected, this heat damages the lens proteins over time, causing them to clump and form a cataract. That heat-driven mechanism makes infrared exposure a primary concern for cataract development in welding work, which is why protecting the eyes with IR-filtering lenses or shields helps prevent this outcome.

Visible light can cause glare and retinal damage in very bright conditions but isn’t the main driver of cataracts from welding. Ultraviolet light does contribute to lens damage with long-term exposure, but the rapid, heat-related changes from infrared are the more direct cause in this context. X-rays can cause cataracts at much higher doses than typical welding exposures, so they’re not the main risk here.