NTL Record

Title	Intermediate visual acuity of presbyopic individuals with and without distance and bifocal lens corrections.
Record ID	39307
Personal Name Creator	Welsh, Kenneth W.; Rasmussen, Paul G.; Vaughan, John A.
Corporate Creator	Civil Aeromedical Institute
Corporate Contributor	United States. Office of Aviation Medicine
Publisher	Civil Aerospace Medical Institute
Publication Date	19770300
Language	English
Abstract	Visual acuity was determined at the intermediate range for older individuals with various combinations of ocular refractive error (nine subcategories) and accommodative power (three subcategories). Subjects (N=249) read numerals ranging in size to measure visual acuity from 20/80 to 20/15 at 51, 76, and 102 cm (20, 30, and 40 in) with 50 fL luminance. Monocular visual acuity scores were determined both with the subject's optimum spectacle lens correction for distance vision (6 m, 20 ft) and near vision (0.4 m, 16 in) and without lenses. For subjects with low accommodative power, neither the distance nor the near lens correction provides normal vision throughout the intermediate range. At 102 cm vision is better with the distance correction, while at 51 cm visions is better with the near correction. At 76 cm neither lens offers normal vision.
Rosap ID	dot:21100
Rosap URL	https://rosap.ntl.bts.gov/view/dot/21100
TRT Terms	Air pilots; Aged; Vision; Vision tests; Contact lenses; Eyeglasses; Distance perception; Eye
General Subjects	Air pilots; Older people; Visual acuity; Vision--Testing; Contact lenses; Eyeglasses; Eye--Refractive errors; Depth perception
Classification	NTL - AVIATION - AVIATION; NTL - AVIATION - Aviation Human Factors; NTL - AVIATION - Aviation Safety/Airworthiness
Geographical Coverage	United States
Report Number	FAA-AM-77-7; DOT/FAA/AM-77/7
Resource type	Tech Report
URL	https://ntlrepository.blob.core.windows.net/lib/39000/39300/39307/AM77-07.pdf
Format	PDF
Database	NTL Digital Repository