Eyelid
The fold of skin that closes over the eye — the small daily curtain on what you let in.
An eyelid in a dream is the dream's image of the small daily curtain on what you let in. The eyelid is what makes the eye possible; the closing is part of the seeing. The dream brings the eyelid when something in your life — a controlled attention, a chosen pause from looking, a private rest — is being held by a small repeated act of shutting that allows the next look to work. An eyelid that closes and opens cleanly is the dream affirming the rhythm. An eyelid that cannot close, the eye staring into everything without rest, is the dream noting that the small protection has failed, and the seeing is being damaged by the inability to look away.