Another method is to put one finger on your upper eyelid in the spot where you feel the top of the lens and the thumb on the lower eyelid over the bottom corner of the lens.
Public health authorities have mined medical data to spot the outbreak of infectious disease, and credit-card companies have found fraudulent credit-card purchases with the method, among other applications.
"To track and spot a wolf from an aircraft, land and then kill it, is not considered to be a fair chase method, " said Alaska Department of Fish and Game commissioner Frank Rue.