Pattern reversal visually evoked responses (VER's) at a frequency of 7 Hz were recorded from 10 subjects. Peak-to-trough amplitudes were measured at centrally fixated field sizes from 1 to 8° for check sizes from 2.5 to 30 min. Check size for maximum amplitude decreased as field size was reduced. The amplitude—check size relation was not necessarily linear across its full range. When using an extrapolation technique for estimating visual acuity, a curvilinear regression may be more appropriate than the assumption of a linear regression.
Received September 15,1981; revision received May 11, 1982.
* Ph.D., Member of Faculty.
W. A. Douthwaite
University of Bradford
Undergraduate School of Studies in
Bradford, West Yorkshire BD7 1DP
© 1982 American Academy of Optometry