Kremlin critic and opposition leader Alexei Navalny said Tuesday that he’s been left almost completely blind in one eye after suffering chemical burns from an attack last week. Navalny, an outspoken critic of Russian President Vladimir Putin who has announced plans to run in next year’s presidential election, was splashed in the face with chemicals last Thursday, an attack that initially seemed to have only involved a harmless antiseptic liquid. On his website Tuesday, however, Navalny said a doctor had expressed certainty that a corrosive chemical had been thrown into his eye, depriving him of 80 percent of his vision in that eye. “I am being actively treated, and there is hope that it will be cured,” Navalny wrote, having vowed earlier this week to run for president even if he loses all sight in the eye. A video of last week’s attack broadcast on a Kremlin-friendly network showed the assailant with his face blurred out, though opposition activists have identified him as a pro-Kremlin activist. Moscow police have opened an investigation into the attack, but Navalny said Tuesday that no arrests have been made and little work has been done to move the probe along.