That’s a really good question! Many people worry about the eye safety of bright light therapy.
You are absolutely correct to be concerned about UV light. Light from this non-visible part of the spectrum can cause a variety of eye problems, especially macular degeneration.
The good news is that most, legitimate light boxes include a diffuser screen that is designed to entirely block out this portion of the wavelength. This is another good reason to only use light boxes that have been clinically tested, both for effectiveness and safety.