Rods induce transient tritanopia in blue cone monochromats

Transient tritanopia is a cone-cone post-receptoral interaction between short-wavelength (S) cones and medium (M) and long (L) wavelength cones. Blue cone monochromats have rods and S cones of normal sensitivity but lack functional M/L cones. All blue cone monochromats tested (n = 8) show significant amounts of transient tritanopia mediated by rods. Attempts to find a similar rod-S cone interaction while silencing the L/M cones in normals yielded only a small amount of S cone sensitivity loss. The results suggest an exaggerated influence of rods on the S cone pathway in the retina of blue cone monochromats.