Sheila?s eyes

?One of the early signs of sleep deprivation is a visual distortion whereby objects appear to shimmer as if covered by a thin film of water. These distortions or illusions are caused by blurred vision coupled with an increased sensitivity to light. I remembered that Sheila had warned me about the freshly waxed floors two nights before. A shining surface is another example of a distortion due to sleep deprivation. When the janitor said that the floors had not been waxed or buffed for more than a week, I knew that Sheila?s eyes were not seeing the world correctly.?

?Ronald K. Siegel, Fire in the Brain: Clinical Tales of Hallucination, 1992.