 Ray et al. 2005 reported a high proportion 39 of reading-impaired children had poor accommodation. The use of yellow filters significantly may have normalized their accommodative response by balancing L- and M-cone input Stromeyer et al., 1997; Stromeyer et al., 2000, and reading skills improved more in those who used yellow filters than a placebo. Simmers et al. 2001 found significantly higher variability in the low frequency component of accommodative response functions among five subjects with visual discomfort symptoms. This variability decreased to normal levels when color filters were used or luminance was reduced. 