Defining vision loss

Vision loss means functional loss

Vision loss affects much more than the eye—a loss of visual function translates to a loss of functional vision.1

Graphic icon of an eye

Visual function

Structural and functional changes at the organ level1

For example, rod dysfunction results in night blindness2

Graphic icon of a person

Functional vision

Vision-related quality of life, including skills, activities of daily living, and social participation1

For example, night blindness limits individuals’ ability to navigate in dimly lit environments, such as a crosswalk at night2

The primary endpoint integrated
measurements of visual function

Combining aspects of vision loss into this single measure quantified what study participants experience on a daily basis—their functional vision.1,3

Photographs are not of actual patients.

"Without night vision, it's difficult for her to move around on her own, making it hard to participate in dances, dinners, or nighttime activities."


For illustrative purposes based on actual patient experience.8