Amplitude of accommodation
From Wikipedia, the free encyclopedia
Amplitude of accommodation (AA) is a measurement of the eye’s ability to focus clearly on objects at near distances (i.e. accommodation). This eye focusing range for a child is usually about 5–7.5 cm (2–3 inches). For a young adult, it is 10–15 cm (4–6 inches). The focus range for a 45-year-old adult is about 50 cm (20 inches). For an 80-year-old adult, it is 1.5 m (60 inches). [1]
The average amplitude of accommodation, in diopters, for a patient of a given age may be estimated by Hofstetter's formula: 18.5 minus one third of the patient's age in years.[1]
[edit] See also
- Convergence insufficiency
- Eye examination
- Negative relative accommodation
- Positive relative accommodation
- Presbyopia
[edit] References
- ^ Scheiman, Mitchell and Wick, Bruce. Clinical Management of Binocular Vision. Lippincott, New York. 1994.
