Is Thoriated Glass Dangerous?

Most smaller lenses with thorium elements pose a negligible risk to human health. However, thoriated glass eyepieces are significantly more dangerous. They can give a very large alpha and beta particle dose to the cornea of the eye, potentially causing cataracts and other problems.

Are vintage radioactive lenses dangerous?

Exposure to these particles over time likely presents a health risk. Until further research is done, radioactive lenses can never be considered truly safe for usage.

Are radioactive lenses safe?

According to the research (below), radioactive lenses are relatively safe. We are regularly exposed to radiation from various sources every day, which combined give a more significant dose than the use of radioactive lenses would: Walking around outside in the sun (main contribution to the annual radiation dose)