How are chickens affected by light?
It seems like they are not affected by fluorescent light frequency. I did not find anything about their visual sampling rate. Their hearing is between 0-200Hz with an average of 86Hz so I guess the visual sampling rate is under this, but that's just a guess.


  We conclude that at the illumination levels used in this experiment,
  the hens did not perceive the flicker of low-frequency light or they
  perceived it but did not find it aversive. Low-frequency fluorescent
  light does not appear to adversely affect the welfare of hens.


1996 - Laying hens do not have a preference for high-frequency versus low-frequency compact fluorescent light sources


  It concludes that there is no evidence that fluorescent or high
  pressure sodium lighting, irrespective of intensity or spectral
  distribution, has any consistent detrimental effect on growth, food
  utilization, reproductive performance, mortality, behaviour or live
  bird quality in either domestic fowl or turkeys, nor in the egg
  production of geese.


1998 - Responses of domestic poultry to various light sources

A monochromatic (LED) light can be more beneficial according to this:


  A significant reduction in egg production was observed in all 880nm
  groups; no differences in egg production and quality were found in the
  other groups. Feed consumption was significantly lower by 7% in all
  0.01 W/m2 groups. We suggest that an important reduction in rearing costs of laying hens may be obtained by using this system.


1998 - New monochromatic light source for laying hens