Simulating visual acuity. The purpose of this page is to give an idea of how blurry your vision is when you don't use your glasses or contact lenses, or when you use a prescription which doesn't match your eyes. This is illustrated by simulating the blurry perception of a Snellen eye chart, which is commonly used to make eye examinations.
A SCAI answered. Fasting for 9 to 12 hours before a cholesterol blood test ensures accuracy in the test. It helps make sure your body does not have extra sources of fat - say, from the ice cream you had for dessert - that could alter the test results.
Come prepared. 1  Wear sleeves that roll up easily. 2  Fasting may be required for lipids (cholesterol, triglycerides, HDL) and glucose tests. 3  Fasting means don't eat any food or drink anything other than water before your blood collection. Continue taking all medication as prescribed and drink plenty of water.