Temp 4

The dichoptic true‐red tetrachromacy glasses enable a transformative shift in color perception by remapping hues onto a two‐dimensional plane—contrasting sharply with the one‐dimensional hue progression characteristic of standard trichromacy. In this engineered system, each hue is defined not solely by its chromatic value on the two‐dimensional plane but also by its independent saturation and luminance levels, thereby expanding the perceptual framework into a four‐dimensional color space that incorporates the novel L-/L+ stereoscopic opponency axis.

For instance, consider a dichromatic gradient spanning blue, cyan, and green. When this gradient is positioned orthogonal to the L+ channel, it gives rise to a distinct trichromatic hue subspace that encompasses a full range of luminosity variations, ultimately integrating with achromatic states. In effect, the addition of the L+ channel orthogonal to the anomalous trichromatic (protanopic) (S, M, and L-) input creates a richer, more nuanced palette than is available to conventional trichromats.

This phenomenon is exemplified in the accompanying program, Trichromatic Hue Gradients of True-Red Tetrachromacy. In this setup, one eye receives a robust trichromatic signal—predominantly mediated by the S, M, and L- cones—while the contralateral eye, equipped with the L+ filter, is limited to deep (i.e. true) red spectral input. Although the absence of the L- contribution in the above example would ordinarily yield dichromatic vision, the complementary L+ channel ensures that the overall percept remains trichromatic. The resulting visual output, while exhibiting slight anomalies due to the engineered spectral partitioning (e.g. imperfect binocular fusion), is sufficiently similar to standard trichromacy to function effectively in everyday perceptual contexts.

In summary, the locally trichromatic subspace—comprising dichromatic gradients of S, M, and L- channels juxtaposed against the orthogonal L+ input—constitutes a vital subset of the higher-dimensional tetrachromatic color space enabled by true-red non-retinal tetrachromacy. This integration of dichoptic inputs not only validates the concept of a two-dimensional hue plane but also underscores the profound implications of engineered spectral filtering in expanding human color perception.