(;  ), also known by the Latinization Alhazen or Alhacen, was an Arab scientist, mathematician, astronomer, and philosopher. Ibn al-Ḥaytham made significant contributions to the principles of optics, astronomy, mathematics, meteorology, visual perception and the scientific method. He spent most of his life close to the court of the Fatimid Caliphate in Cairo and earned his living authoring various treatises and tutoring members of the nobilities.