Have you ever had visions?

Yes, during meditation, and having an out of body experience.

Also many lucid dreams, some, very short, to the level of not understanding the difference between dream and "real" world.

 

i have bad vision and use contact linces

 

It's a dream in which you are conscious of dreaming, so you're awake to the fact that it is not "real" life.

Lucid dreams are different in kind and intensity, i had many, but all very short. It's kinda like being in a cartoon, everything is very colorful and vivid.
Also, i don't thin lucid dreaming is the same thing as astral travelling or having an obe.

If you want an easy tip to try having a lucid dream, you have to watch your hand while you're dreaming, for some reason if you're able to do this you will awake in the dream and start lucid dreaming. To do it you should watch you hand many times during the day and ask yourself "is this a dream?" so the possibilities of doing that during a dream will arise.