COMPONENTS OF VISION LOSS

While visual acuity is an important measure of macular function, it describes just a single aspect of vision rather than a comprehensive assessment of visual function. Understanding other components of vision will help guide therapy and educate patients about the visual resources they still have, emphasizing visual function that remains rather than what has gone.

Visual acuity

• The ability to distinguish details of objects
• A measure of clarity or clearness of vision

Contrast sensitivity

• A measure of the ability to see low contrast patterns (i.e. the better your contrast sensitivity the greater ability you have to see objects with little contrast)
• Increasingly recognized as an important factor influencing the quality of vision

Visual field

• The entire area that can be seen, including central and peripheral vision

Other components

• Fixation: the ability to focus on a fixed point - very important in tasks such as reading
• Glare recovery: the time taken to regain visual function after exposure to a bright light.
• Stereoacuity: fine-detail depth perception, important in tasks such as threading a needle
• Color perception: the ability to distinguish among different shades of colors