We hung these in low tree branches and shrubberies on Halloween night and two nights later, they were still glowing strong! The connection between the eyes battery unit and the little hanging hook is not strong, and the eyes battery unit fell to the soft ground several times, causing the eye casings to pop off - but everything popped right back together and a little electrician's tape around the hanging hook fixed the weak connection problem.
Inside, the light was dim but outside in the dark, the eyes glowed bright and strong and looked suitably creepy, peering out of the darkness.