Why can using a black light lamp without a proper filter cause damage to the eyes?

Using a black light lamp without a proper filter can lead to eye damage primarily because it emits ultraviolet (UV) light. UV radiation is not visible to the human eye, but it is harmful, especially in high intensities or prolonged exposure. UV light can cause various eye issues, including photokeratitis (a painful condition akin to a sunburn on the cornea), cataracts, and other serious conditions affecting vision over time.

The other options, while they might present potential concerns in different contexts, do not directly address the specific risks associated with black light lamps. Although bright white light and infrared radiation can cause discomfort or harm to the eyes, they do not have the same structural effects on the eye as UV light. Excessive heat can be a concern, but it is not typically related to the function of black light lamps in the same way that UV exposure is significant for eye safety. Thus, the primary risk linked to using a black light without a proper filter stems from its emission of ultraviolet light.