Well, actually tanning can be very bad for your health, especially for your eyes. So you need to take some ways to protect your eyes. Generally speaking, because of the uv rays omitted by tanning bed, it will affect eyes, leading to some serious eyes problems. For example, it can lead to eye cancer, which is a potential consequence of excessive UV ray exposure. According to some researches, photoconjunctivitis, inflammation of the cornea, cataracts, and a flesh-like growth on the eye's surface can occur too. So it can be dangerous without any protection. Maybe you can just wear a pair of eye patch to protect your eyes from being invaded by uv rays. Also, mask can be good too.