TGFBR2 and keratoconus: The finding of the eye-rubbing experiment indicated the importance and the significance of the involvement of environmental factors in the pathogenesis of the CE-like phenotype by showing the similarities between the classic signs found in acute/advanced CE, including keratoconus, keratoglobus, and a PMD called Acute Corneal Hydrops (ACH), after the disorder was triggered by the genetic defect of TGFBR2 in the corneal stroma.