Premium
Video‐photorefraction: the relationship between blur circle diameter and refractive error
Author(s) -
Jennings Deborah S.,
Jennings J. A. M.
Publication year - 1995
Publication title -
ophthalmic and physiological optics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.147
H-Index - 66
eISSN - 1475-1313
pISSN - 0275-5408
DOI - 10.1046/j.1475-1313.1995.9400020z.x
Subject(s) - refractive error , optics , pupil , pupil diameter , computer vision , mathematics , artificial intelligence , computer science , physics , visual acuity
Summary When using a videorefractor (VPR‐1) the margins of the defocused blur circles are sometimes poorly defined and difficult to locate. To investigate the effect this may have on the apparent refractive error, the relationship between blur circle diameter and refractive error was found by videoing circles of known size and inputting these data as pupil and blur circle diameters. The results indicate that for accuracy of 0.50 D blur circles need to be defined to ≃ 1 mm.