We determined the foveal optical modulation transfer functions of the human eye (O) for pupil sizes of 1–8 mm by using two simple psychophysical techniques. <i>O</i> as a function of spatial frequency <i>f</i> could be described by exp[−(f/f<sub>c</sub>)<sup>n</sup>] at any pupil size in our data as well as in the data available in the literature [J. Physiol. (London) <b>186</b>, 558 (1966); Opt. Acta <b>21</b>, 395 (1974); Vision Res. <b>33</b>, 15 (1993); J. Opt. Soc. Am. A <b>11</b>, 246 (1994)]. When all these estimates of f<sub>c</sub> and <i>n</i> were pooled the parameters were found to depend on the pupil diameter as f<sub>c</sub>= 16.6−1.49p and n=exp(0.840/p−0.318). This result indicates that at 1 mm O(f) is close to the diffraction-limited system.
© 1998 Optical Society of America
Jyrki Rovamo, Heljä Kukkonen, and Juvi Mustonen, "Foveal optical modulation transfer function of the human eye at various pupil sizes," J. Opt. Soc. Am. A 15, 2504-2513 (1998)