When Jerry Berrier dreams, he hears and touches and smells and talks, but he doesn’t see. Blind since birth, he rarely remembers his dreams, however, because his sleep has been so poor.

At 15, Berrier had both of his eyes removed and lost the little light perception he had as a child. Ever since, the Everett resident, now 60, has battled a vicious sleep cycle — a few days of sleep followed by weeks of hardly any. The bouts of sleeplessness come suddenly and subside without warning. When they hit, Berrier can’t sleep more than a couple hours a night, no matter how tired he is.