Cataracts in the 13-lined ground squirrel (IMAGE) NIH/National Eye Institute Caption Study researchers observed that in the 13-lined ground squirrel, a cataract (red arrow) formed in the animal as it hibernated at low temperatures. The cataract, which is a clouding of the eye's lens, cleared after the animal was rewarmed Credit Wei Li, Ph.D. Usage Restrictions No restrictions. License Public Domain Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.