Various research activities concern the effects of partial or total attenuation of violet and blue light on visual performance. Some results are reported in the publications page on this site.
The optical transmittance spectra of blue-violet filtering lenses and clear ones, both contact lenses and ophthalmic lenses, have been investigated and compared with the spectral response of photo-receptors, with the absorption of the macular pigment, and that of the ganglion cells. The attenuation of blue and violet light has been discussed taking into consideration the chromatic aberration of the human eye and the transmittance of the ocular media both in the young and the elderly. For example, two articles focus on contrast sensitivity, its trend with age, and the effect of blue-violet filters. One of the main conclusions concerns the role of the subject’s baseline contrast sensitivity (measured with a clear lens) in determining a possible improvement or worsening of contrast sensitivity with the use of filters.