Biology Reference
In-Depth Information
8
6
4
2
0.1
0.2
0.3
0.4
0.5
0.6
0.7
% Rhodopsin still bleached
Fig. 24.1 Relationship between absolute threshold intensity of the rod
monochromat K. N. obtained in the region of linear slope (wavelength
of test stimulus was 550 nm; size, 1 x 2 º; exposure time, 0.5 s; and
retinal location 7 º in the nasal field of view) and concomitant fraction
of rhodopsin still bleached calculated from Rushton and Powell (1972).
Time constant of rhodopsin regeneration adopted was 360 s.
concomitant amount of bleached rhodopsin
B
obtained during the
major, middle part of the long-term dark-adaptation curve could
be described by a power function:
T
= c
B
n
where c is a constant and the exponent
n
has a value between 3
and 4 (see Stabell & Stabell,
1996
). (The exponent
n
of the power
function could not be given an exact value due to the low reliability
