I am currently studying A level biology, and we have just learnt about myelinated neurons, and have been taught about the possitives, and I was just wondering if there was anything bad about them? Also if they are so good, then why aren't all of our neurons myelinated? Thanks in advance, Josh.

I have very vivid dreams where I can in detail, see or visualise my complete surroundings.

If a person was born blind what would they dream of?

Also, If a person lost there sight later in life, would their lack of vision while they were blind effect what they experience dreams?