This preventing or treating agent of the keratoconjunctival trouble is provided by containing an Nrf2-activating substance as an active ingredient, wherein, Nrf2 (NF-E2 related factor 2) is a transcription factor inducing and controlling the gene expression of the second phase enzyme of a foreign material-metabolizing system, directly detoxifying an electrophile substance, an antioxidation enzyme such as hemeoxygenase, etc. Nrf2(NF−E2 related factor 2)は、親電子性物質を直接解毒する異物代謝系第2相酵素およびヘムオキシゲナーゼといった抗酸化酵素等の遺伝子発現を誘導制御している転写因子であり、該Nrf2の活性化物質を有効成分とする角結膜障害の予防または治療剤。 - 特許庁