As a proof of concept of hypotheses and interpretations of the results, an achromatopsia patient (ACHM) with CNGA3 mutations (c.1585G>A ➔ p.Val529Met and c.1641C>A ➔ p.Phe547Leu heterozygous, respectively) served as an example of non-functioning cones, and a patient with progressive glaucoma as an example of ganglion cell damage with preserved photoreceptors. Here, CNGA3 is linked to glaucoma.