Effect of a central fusion stimulus on fixation disparity.
Fixation disparity (FD) measurements were made with a 1.5 degree diameter fusional stimulus both with and without a central fusion stimulus. Measurements were made at 40 cm with no prism, 5 delta base-in (BI) and base-out (BO), and 10 delta BI and BO, on a group of asymptomatic subjects. The central fusion stimulus results in less variable measurements and a flatter slope of the fixation disparity curve (FDC). Implications of the use of the central stimulus for clinical measurements are discussed.
S J
SJ
Debysingh
P L
PL
Orzech
J E
JE
Sheedy
D000065:Accommodation, Ocular; D000328:Adult; D003290:Convergence, Ocular; D005133:Eye Movements; D005403:Fixation, Ocular; D006801:Humans; D012016:Reference Values; D014794:Visual Fields