A 76-year-old man with bilateral practolol-induced dry eyes developed atypical acute bilateral corneal calcification. Serum calcium, phosphate, and urea levels were within normal limits. The calcium deposition progressed rapidly to involve 90% of the right cornea. Right penetrating keratoplasty was performed with subsequent visual rehabilitation of the patient. Left tectonic penetrating keratoplasty was performed 8 weeks later after corneal perforation. The corneal specimens were examined by light and electron microscopy, which showed an atypical calcareous degeneration involving Bowman's layer as well as the full thickness of the stroma. Transmission electron microscopy showed the granular calcification to consist of extracellular, radially orientated aggregates of fine, needle-shaped crystals. Both transplants remained clear with no evidence of postoperative recurrence. To our knowledge this is the first report of bilateral penetrating keratoplasty for acute calcareous degeneration.