tired eyes/flickering

Hi.  I'm studying neuroanatomy and have an eye question related to something my friend and I both experience.  When we are tired, we are prone to seeing flickers in artificial light (flourescent).  I am guessing there is some preferential attention issue here - we pay more attention for some reason to rods or cones at different times and that changes if we are really tired?   And the effervescent four year old in me wants to know why :-)

[John C Hagan III, MD, FACS, FAAO]

It is something that others have mentioned in postings here in the last year. I cannot explain it on the basis of my understanding of neuro-anatomy of the eye. Perhaps related to the speed of "flicker fusion"

JCH MD