D. Rods take about 30-40 minutes for complete dark adaptation. Cones take about 5-10 minutes for light adaptation.

A. Ricco’s law states that the number of photons is the same for all stimulus sizes that are less than a critical diameter. This varies as stated above. Bloch’s law describes a critical time threshold for stimulation. Ferry-Porter law states the critical flicker frequency with the log of retinal illumination. Granit-Harper law states that the CFF increases as the stimulus area increases.

B. Spherical aberrations are the cause of distortion and reduced acuity in a dilated pupil. Small, miotic pupils are affected by diffraction although miotic pupils do increase depth of focus.

D. The Nagel Anomaloscope is the only color vision test that is able to distinguish between dichromats and anomalous trichromats. The Farnsworth and HRR are able to diagnosis both b/y and r/g color defects but cannot distinguish between the two above. Ishihara can only diagnose red-green defects.

C. The low frequency cut off is due to lateral inhibition in the retina. Lateral inhibition is produced by the interneurons: horizontal and amacrine cells. The high frequency cut off is due to optical aberrations and photoreceptor spacing.