Garip-Kuebler A, Halfter K, Reznicek L, et al. - Researchers conducted this observational, retrospective study to examine the subclinical findings of dysthyroid optic neuropathy (DON) and look for early signs for optic nerve compression in patients with Graves’ orbitopathy. Between 2008 and 2019, the medical charts of 24 patients (32 eyes) with a diagnosis of DON were included. The authors found that tritan deficiency obtained with a standardised color vision test by Arden was the earliest pathological sign in the subclinical cases. It was noted that the sensitivity of the color vision test for protan was 20% and for tritan was 96.67% in the subclinical phase. Changes in vision affecting the blue-yellow (tritan) colors resulting from the compression of the optic nerve, as well as in patients with normal VF tests, have been shown to be a reliable early sign of DON.