The relative sensitivity of the following tests to contact lens induced oedema was assessed: Pachometry, biomicroscopy, high contrast visual acuity, disability glare using the Brightness Acuity Tester and straylight (10 degree angle) using the van den Berg Straylightmeter. The mean and 95% confidence limit baseline data for the vision tests were recorded. The subjects then wore a 0.37mm thick hema lens on one eye patched for three hours. The other eye was used a control. Corneal swelling of 11% was measured when the lens was removed. The six tests were then consecutively performed for the next two hours. Tests were randomised between subjects. The corneal swelling % was extrapolated from the corneal deswelling versus time regression line to give the value when each of the vision tests returned to baseline. This provides an indication of the sensitivity of each of the tests. The mean corneal swelling values were: Visual acuity ~12%, both disability glare tests 8%, straylight 4.8% and slit-lamp examination 4.1%. The sensitivity of the pachometer (1.7%) was determined by the 95% confidence limits of its repeatability. While pachometry is the most sensitive test, these results suggest that straylight may be a useful additional technique for assessing corneal oedema.