Uncorrected visual acuity will be assessed at distance and intermediate (60 cm) using a standardized eye chart. The number of lines in the eye chart that the participant correctly identifies will be measured. The test will be performed both binocularly and on 1 eye at a time by covering the eye not being tested. Distance and intermediate visual acuity will be measured under normal light conditions.

Depth of focus (DoF) is defined as the distance in diopters that a viewed object can be moved towards or away from the eye until the object is no longer judged to be in focus. DoF will be assessed using either wavefront aberrometry or according to the following instructions. Distance: Set the distance spectacle prescription in the refractor head/trial frame. Have the participant look at the 6/9 (0.6) Snellen letter. Increase the plus sphere power until the participant reports blurring (+a diopters). Repeat using negative lenses (-b diopters). Remove the negative sign in front of b. Depth of focus at distance = (a+b) diopters. Near: Set the distance spectacle prescription at +2.5 diopters in the refractor head/trial frame. Have the participant look at the J2 print at 40 cm. Increase the plus sphere power until the participant reports blurring (+x diopters). Repeat using negative lenses (-y diopters). Remove the negative sign in front of y. The depth of focus at near = (x+y) diopters.

Uncorrected visual acuity will be assessed at distance using a standardized eye chart under normal light conditions. The test will be performed both binocularly and on 1 eye at a time by covering the eye not being tested.

The Patient Reported Outcome Questionnaire includes 29 questions assessing subject satisfaction of their vision and the need for eye glasses in order to perform daily tasks.

Pupil size and appearance will be evaluated by wave-front aberrometer. Examination will be conducted at near mesopic conditions, in low but not quite dark lighting situations at a fixed setting on the light meter. Mesopic light levels range from luminance of approximately 0.001 to 3 cd m-2, an appropriate and fixed setting will be selected, that reflects most night-time outdoor and traffic lighting scenarios. An examination of pupillary function includes inspecting the pupils for equal size (1 mm or less of difference may be normal), regular shape, reactivity to light, and direct and consensual accommodation (PERRLA [D+C]; Pupils Equal and Round, Reactive to Light and Accommodation [Direct and Consensual]).

Assessment of the stability of pre-corneal tear film will be conducted using non-invasive break up time (NIBUT) and tear meniscus height. NIBUT is measured with instruments such as a Keratometer, a hand-held Keratoscope, or a Tearscope. After a blink, the reflection observed with these instruments is clear and crisp when the ocular surface is free from any irregularities. NIBUT is defined as the interval between the opening of the eyes and the moment when an irregularity is observed. NIBUT values < 10 seconds indicate dry eyes. Tear meniscus height (TMH) can be measured with a slit-lamp biomicroscope. A slit lamp image of the lower TMH can be photographed or captured electronically and later measured directly on screen and corrected for magnification. The lower TMH represents the total volume of tears at the ocular surface. Heights of less than 0.2 mm indicate reduced tear volume. A tear meniscus with a scalloped edge is often associated with a dry eye.

Testing the visual fields will consist of confrontation field testing in which each eye is tested separately to assess the extent of the peripheral field. Visual field is assessed in each eye separately. The participant occludes 1 eye while fixated on the examiner's eye with the non-occluded eye. The subject is then asked to count the number of fingers that are briefly flashed in each of 4 quadrants (left, right, up, and down).