President Trump is scheduled to be in Philadelphia on Tuesday, September 15, 2020 at The National Constitution Center (NCC) in the Independence Mall area. Increased police presence is anticipated in Center City throughout Tuesday afternoon and evening. Please allow extra time if you are going to Wills Eye. Please be advised of area street closures to vehicles beginning at 1:00PM on Tuesday 9/15. Pedestrian access will also be limited in the area. This is subject to change and area restrictions, which could widen, will be lifted once the President departs the NCC. There are also demonstrations planned for Tuesday 9/15 around Independence Mall as well as City Avenue.

Dark Adaptation Test

The Dark Adaptation Test is a psychophysical test used to determine the ability of the rod photoreceptors to increase their sensitivity in the dark. This test is a measurement of the rate at which the rod and cone system recover sensitivity in the dark following exposure to a bright light source.

The test is performed in a completely dark room. The patient will sit with their chin on a chinrest while looking into the Dark Adaptation machine. During the test a subtle bright light will blink and the patient will hit a button when they see that light. The light will flash at different intensities to test the threshold of the patient’s rod function.