The distance from the posterior margin of the retina to
the focal plane (lens–F0 distance) was obtained by subtracting
dH0 from the estimate of f0, and was 201 ± 16 lm in
sections and 197 ± 19 lm in wholemount preparations
(Table 1). The distance was larger by a factor of 3 than that
obtained in a previous study by observation of a light path
through the isolated corneal lens (Toh & Okamura, 2001).
If we suppose a homogenous matrix for the corneal lens, a
refractive index 1.6 is less likely, but a higher value is
expected.