• Anomaloscopic color matching was performed in 57 protanomalous boys. The relative luminous efficiencies of their mothers were measured by flicker photometry to clarify the characteristics of protanomaly carriers. The sensitivity loss of protanomaly carriers in the long wavelength region had a highly significant correlation with the anomalous quotients (AQs) of their protanomalous sons. This correlation means that both the luminous efficiencies of the protanomaly carriers and the AQs of their sons are determined by the same "anomalous" cone pigments.
Yasuma T, Tokuda H, Ichikawa H. Abnormalities of Cone Photopigments in Genetic Carriers of Protanomaly. Arch Ophthalmol. 1984;102(6):897-900. doi:10.1001/archopht.1984.01040030717027