Temporal changes in tear film structure (e.g., drying of the tear layer) can distort the optical wavefront as it passes through the tear layer and subsequently reduce contrast sensitivity.1 Theoretically, any substance applied to the tear layer that alters its structure could affect contrast sensitivity. Previous work in our lab has demonstrated that Refresh Liquigel when applied to the tear layer of non-contact and contact lens wearing subjects can decrease contrast sensitivity.4, 5, 7 In this study, we propose to examine the effects of a new investigational artificial tear on contrast sensitivity and optical aberrations for up to 30 minutes after administration into the tear layer of normal and dry eye subjects. A questionnaire will also be used to determine the opinions of the subjects concerning this new artificial tear.