Well, of course, you should listen to the words what your mum has told you, and do not go to tanning after the eye surgery. As we know that there will have many eye problems by enjoying tanning bed. For example, because of the uv rays omitted by tanning bed, it will affect eyes. It can damage your eyes, leading to eye cancer, which is a potential consequence of excessive UV ray exposure. Also, photoconjunctivitis, inflammation of the cornea, cataracts can be possible. And after the eye surgery, your eyes are more sensitive than normal; it will make your eyes suffer those problems above, by having tanning. So just do not have tanning after surgery.
No, you should listen to your mother's advice. You should not go tanning after the laser eye surgery which will be bad for your eyes. You need to have the good rest for the eyes by having the good diet and then you will get the basic recovery after one week. But you need to wait for about one month of general recovery and then go tanning.
Well, I think your idea is much too risky and ridiculous, because as you can see, lasik eye surgery is one of the most dangerous surgeries in the world which would have lots of impacts on your eyes, and it requires a lot of care to your eyes after the operation. Perhaps 2 months later you are good to go, for the tanning lights and equipment would generate some damage to your eyes, and make the situation worse. Just try to follow the doctor's advice and instructions.