Objective Evaluation of Ocular Surface Lubricants in Two Environments

• Tear Film Properties [ Time Frame: Measurements: There is no time restriction between the screening and 1st measurement. 6 measurement visits occur approximately 7 days apart but can range from 3 to 14 days. The time between visit 3 and 4 are not be closer than 3 days, but no upper limit. ] [ Designated as safety issue: No ]

  The wavefront sensor instrument measures the eye's ability to create a sharp image.

  Ellipsometer (E) data identifies changes in lipid thickness and refractive index over the cornea.

  A thermal (T) imaging system provides thermal maps of the subject's eyes and face adjacent to the eyes.

  A questionnaire (Q) will ask subjects about their test eye's comfort. Subjects will be asked the questions prior to instillation of the eye drop and after each set of measurements.

  
  

Drug: B & L Soothe Lubricant Eye Drops
Eye Drop
Drug: Liposic EDO
Eye Drop
Drug: OcuFresh Eye Wash
saline drop

This study will objectively evaluate ocular surface lubricants in subjects with dry eye syndrome. Lubricants contain compounds that are purported to improve dry eye symptoms, although objective data is not available. The investigators seek to objectively evaluate the effectiveness of two lubricants and compare the results to a saline eye drop (control).

The investigators will assess the tear film and lipid layer before and after the administration of three products in the same eye of 25 dry eye subjects using wavefront sensing, ellipsometry, and thermal imaging in a "normal" environment. Subsequently the investigators will change the environment to one that causes the subjects' ocular surface to experience "evaporative stress" (warmer, less humid and greater air flow) and perform the before and after drop administration measurements with the same three products in the same eye as the first environment.