Prior to his election as pope in 2005, Ratzinger had hoped to retire—on account of age-related health problems, a long-held desire to have free time to write, and the retirement age for bishops (75)—and submitted his resignation as Prefect of the Congregation for the Doctrine of the Faith three times, but continued at his post in obedience to the wishes of Pope John Paul II. In September 1991, Ratzinger suffered a hemorrhagic stroke, which slightly impaired his eyesight temporarily but which he recovered completely. This was never officially made public—the official news was that Ratzinger had fallen and struck his head against a radiator—but was an open secret known to the conclave that elected him pope.