Seven patients are described who presented with the typical fundus finding of gold-colored crystals in the superficial layers of retina in the macular area (characteristic of canthaxanthin retinopathy) without having taken canthaxanthin-containing drugs. Canthaxanthin used as a food additive is discussed as a possible cause of the crystal deposition. There may be a rather high individual tendency to develop crystal deposition, possibly related to a metabolic defect affecting canthaxanthin kinetics or to pre-existing changes in the retinal pigment epithelium. In one patient a slight decrease in crystalline deposition was observed in the course of four years.

The principle of contact lens ophthalmoscopy was discovered in 1703; the fundus contact lens was very nearly invented in 1844. Coaxial illumination was applied in 1823 and improved in 1841 by including a mirror, while, the first usable ophthalmoscope was designed in 1847. This article pays tribute to the virtually ignored services of Méry, Kussmaul, Purkinje, Hofmann, and Babbage.

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