<jats:sec id="s1"><jats:title>Background/aims</jats:title><jats:p>We developed a novel technology consisting of violet light (VL)-emitting glasses and defined the combination of VL irradiation and riboflavin treatment as KeraVio. Our goal was to evaluate the clinical results of KeraVio in patients with progressive corneal ectasia.</jats:p></jats:sec><jats:sec id="s2"><jats:title>Methods</jats:title><jats:p>Eyes were exposed to VL (375 nm, irradiance 310 μW/cm<jats:sup>2</jats:sup>)-emitting glasses for 3 hours daily for 6 months, and a riboflavin solution was administered onto the corneal epithelium six times during each 3-hour VL irradiation. The primary end point was a change in the maximum keratometry (Kmax) value over 6 months compared with that over the 1 year before baseline.</jats:p></jats:sec><jats:sec id="s3"><jats:title>Results</jats:title><jats:p>The efficacy of KeraVio was evaluated in 20 eyes with severe progression, and its safety was evaluated in all 40 eyes. The mean changes in Kmax over the 1 year before baseline and during the 6-month observation period were 6.03±3.41 dioptres (D) and −0.81±3.34 D, respectively (p=0.002). At 6 months, the Kmax value decreased by more than 2 D in 4 eyes (20%), remained within 2 D in 13 eyes (65%), and increased by 2 D or more in 3 eyes (15%). The corneal stromal demarcation line was identified in 16 eyes (80%), and its depth was 206.3±54.9 μm at 1 month. No significant decrease in endothelial cell density, lenticular opacity or transient corneal haze was noted.</jats:p></jats:sec><jats:sec id="s4"><jats:title>Conclusion</jats:title><jats:p>Based on our 6-month results, daily treatment of progressive corneal ectasia with KeraVio can halt disease progression without any safety concerns.</jats:p></jats:sec><jats:sec id="s15"><jats:title>Clinical trial registration number</jats:title><jats:p>jRCTs032180217.</jats:p></jats:sec>