The extent to which compensation for the prismatic effects of spectacle lenses is maintained.
OBJECTIVE
The ability of subjects to compensate for the visual displacement caused by the prismatic effects of spectacle lenses was studied over 4 days.


METHODS
Subjects were made myopic using contact lenses and then corrected with spectacles. Pointing behavior was used to assess directional localization. Compensation for the refractive lenses was induced by showing subjects their pointing errors.


RESULTS
Compensation was maintained for 4 days in 3 of 4 subjects despite 24 h of normal viewing between testing sessions. One subject demonstrated a negative directional aftereffect which has not been previously reported in studies of spectacle lens adaptation.


CONCLUSIONS
Compensation for the prismatic effects of spectacle lenses can be maintained for several days in some subjects. This compensation may be functionally useful for some patients who switch between spectacles and contact lenses.
Fogt
N
N
The Ohio State University, College of Optometry, Columbus 43210-1240, USA. fogt.4@osu.edu
Henry
J W
JW
D000065:Accommodation, Ocular; D000328:Adult; D005139:Eyeglasses; D005500:Follow-Up Studies; D006801:Humans; D009216:Myopia / Q000503:physiopathology / Q000628:therapy*; D055095:Optics and Photonics; D012029:Refraction, Ocular