Optics and light sources is something that I have a great deal of professional experience from so this is not just stating opinion.
One should never look straight into any high powered LED irrespective of wavelength (colour), the light intensity and the small active area from these are able to cause retinal damage to your your eyes. Even most glasses provide little protection from the intense little spot of light (welders glasses should be OK though).
Link to one info source among many.
Like you suspect newoldguy, the reflected light from the LEDs in the visible and NIR/IR doesn't pose any danger. The UV component, even from what is reflected however, will/may cause corneal damage called ultraviolet keratitis which is basically sunburn of the corneal epithelium. This damage does heal but prolonged repeated exposure to UV is known to be linked to cataracts as well as a host of other eye disorders.
The reflected UV intensity is so low though that any half way decent UV protecting sunglasses will do the job just fine. No lab grade protective glasses or welding glasses are needed.
Naturally the UV hazard only applies to LED grow lights that actually incorporate UV LEDs, most don't so most do not require protective glasses. The "don't stare into them directly" part does apply to all LED grow lights.
Vis vobiscum.
... paddy is a happy camper today
Man, the things we just survive in life, eh? Glad you healed Dutty.
