A 32 year old man came to the emergency department for a recent decrease in vision in the eye of the left eye coinciding with the appearance of a brownish lesion in this eye. His ophthalmological history included a penetrating trauma to the eye three years earlier, which had been sutured in our centre. On examination, visual acuity was 0.1, which improved to 0.5 with steno-opia. Biomicroscopy of the anterior segment showed an iris cyst occupying half of the anterior chamber, the anterior wall of which contacts the corneal endothelium, a 6 mm linear corneal scar that respects the visual axis and a clear lens. The intraocular pressure (IOP) is 14 mmHg in both eyes. The fundus as far as the lesion can be explored is normal, as is the B-mode ocular ultrasound of the posterior segment. The Stratus OCT image shows a thin anterior wall in discontinuous contact with the corneal endothelium and clear contents of the cyst. The lesion was clinically diagnosed as an epithelial iris cyst. The patient was operated by aspiration puncture of the cyst with a 30g needle, viscodissection of the cyst to separate it from the corneal endothelium and reformation of the anterior chamber followed by ab externo photocoagulation in the same surgical act of its collapsed walls using non-confluent, high power, long term impacts until tissue retraction was observed. No intense burns were performed and no confluent treatment was applied to avoid extensive atrophy of the underlying iris. Postoperatively, the patient had moderate intraocular inflammation that responded to hourly topical corticosteroids and formation of a wide posterior synechia at XII h without cataract development and with significant visual improvement. Six months after the operation, the visual acuity was 0.8 and the biomicroscopic examination showed a vertical oval pupil with posterior synechiae from X to II h as the only sequelae. There are no signs of recurrence of the lesion.