Can anyone identify this sci fi book from a synopsis??

Anyone on here read a lot of obscure science fiction books? Specifically young adult science fiction books?

When I was a kid, I went to the library and picked out a science fiction book and sat down to read it there. It couldn't have been too long, as I read it in one sitting. However, I was reading at a college level at that point, so I don't think it was just a little kid's book, either. If my hazy memory serves me, it was a paperback about the size and thickness of a DVD case.

Here's what I remember about it:

The main character was a young boy. He lived in a society (city?) enclosed within a "bio-dome" of some kind. He had been told about what lay outside the dome (post apocalyptic? toxic fumes? dangerous animals?) and that no one could survive out there. The inhabitants of this dome all had these plugs or ports installed in the back of their heads when they were very young, and as they grew, they had more and more of these "devices" attached to them which increased memory or intelligence or something. They never saw the sun for some reason, and no one did any sort of physical activity at all, so everyone, even the children, were very atrophied and pale.

This boy escapes from the dome somehow (accidentally or running away) and finds that the outside world is wild, but far from uninhabitable. He meets some "savages" of course, and ends up living with them. He gets stronger, gets a tan, and removes the implants somehow. I'm sure he goes back to the dome at some point, but I really don't remember much of the end.

That book really made an impression on my subconscious, and I would dearly love to read it again as an adult, but unfortunately, I have absolutely no idea what the title is or who wrote it.

If anyone has any ideas, please email me at [email protected]. I may not remember to check back here, so email would be best. Thank you!!

Eileen