7. Some friends tell me a cataract surgery can be
    performed by a laser.
    Is that true?

At present, there is no laser that can safely remove a cataract. On and off there are experimental studies with lasers, but the most advanced method of cataract removal is still via phacoemulsification. Some patients do get a return of blurred vision some time after cataract surgery and that is due to opacification of the capsule holding the lens. In those cases, yes we can use a laser to treat the condition.