The Staining Grid is an easy-to-use reference tool informing the eye care practitioner as to the level of biocompatibility of various contact lens/multipurpose solutions. It appears as a "grid" with the solutions listed across the top and the lens materials in the first column. The percentages which appear in each cell represent the average percentage of the cornea which was stained 2 hours after lens/solution insertion. For information on our testing procedures please see the methodology question in the Frequently Asked Questions section of this site. Also, read the section explaining staining scales and how to cut through the staining scale confusion.