Corneal pigmented (brown) arcs were observed in two orthokeratology patients, both aged 23 years. The preorthokeratology refractive data were OD −5.25 −0.50 × 175 and OS −6.00 −0.75 × 5 for patient A and OD −3.75 −1.00 × 10 and OS −3.00 −1.25 × 175 for patient B. The time course for the development of the arcs was different not only between the two patients but also between the two eyes of patient A. For patient A, the pigmented arc was observed in the left eye 1 week after commencement of lens wear and was not observed in his right eye until a visit about 6 weeks later. For patient B, the arcs were only observed at an aftercare visit about 28 weeks after commencing lens wear. Both patients had been participating in an orthokeratology research study for about 12 months and decided to stop the treatment after completion of the study. The pigmented arcs were no longer present when they returned about 2 months later for assessment of the regression of the refractive and corneal changes induced by the procedure.