<qa>  What is the standard eye examination?Participants will have a standard eye examination, including a check of visual acuity and eye pressure. The retina will also be examined and photographs of the cornea may be taken. For the DLS test, the subject sits in front of the device and looks at a yellow-green target while the cloudiness of the cornea is measured. Subjects will be tested four times. The entire procedure takes less than 30 minutes. 