Biology Reference
In-Depth Information
1
Cone
0
1
2
Rod
3
500
600
700
nm
Fig. 3.1 Absolute spectral threshold curves obtained during the
cone-plateau period (○) and in a completely dark-adapted eye (● ) at 30°
extrafoveally using a 1 × 2° test field exposed for 0.5 s.
The defence of the duplicity theory presented under these three
headings represented von Kries's major arguments in favour of the duplicity
theory, but under a fourth heading, 'Special items', he also pointed to
several minor arguments. For instance, in accord with Parinaud (
1884b
),
he emphasized that the variation of the size of the photochromatic interval
with wavelength and with dark adaptation could easily be explained by
