This is the year when Jack M. Elkin, an actuary, found an algebraic solution to Alhazen's problem.

This is the year when Friedrich Risner published 'Opticae thesaurus: Alhazeni Arabis libri septem, nuncprimum editi; Eiusdem liber De Crepusculis et nubium ascensionibus', which included the first printed Latin translation of Alhazen's 'Book of Optics'. This publication played a crucial role in disseminating Alhazen's work to European scholars and contributing to the scientific revolution.

Date of publication of 'Dream Pool Essays' book of Shen Kuo that includes the description of camera obscura.

This is the approximate death date of Abu Ali al-Hasan ibn al-Hasan ibn al-Haytham, known as Ibn al-Haytham or Alhazen. He died in Cairo, Egypt, during the Fatimid Caliphate, at around the age of 75. His death marked the end of a prolific career that significantly advanced our understanding of optics and the scientific method.

This is the approximate year when Alhazen wrote 'The Model of the Motions of Each of the Seven Planets'. Only one damaged manuscript has been found, with only the introduction and the first section, on the theory of planetary motion, surviving.

This is the year when Ibn al-Haytham finished writing Al-Shukūk ‛alā Batlamyūs, variously translated as Doubts Concerning Ptolemy or Aporias against Ptolemy.

This is the year when Ibn al-Haytham started writing Al-Shukūk ‛alā Batlamyūs, variously translated as Doubts Concerning Ptolemy or Aporias against Ptolemy.

This date corresponds to Safar 415 A.H. when Ibn al-Haytham wrote a copy of Apollonius' Conics. The existence of this copy, found in Aya Sofya (MS Aya Sofya 2762, 307 fob.), demonstrates Ibn al-Haytham's deep engagement with classical mathematics and geometry. It provides insight into his scholarly activities during this period and his dedication to preserving and studying important mathematical texts.

This is the approximate end date when Ibn al-Haytham completed writing his most influential work, the Kitāb al-Manāẓir (Book of Optics). The book was written over a period of approximately ten years and covers a wide range of topics related to optics, including vision, light, color, reflection, and refraction. The work is a seven-volume treatise on optics and is considered one of the most important contributions to the field of optics in history.

This is the year when Caliph Al-Hakim died. It is significant because Ibn al-Haytham, who had previously fallen out of favor with the Caliph and was said to have been forced into hiding, had his confiscated possessions returned to him following the Caliph's death. This marked a turning point in Alhazen's life, allowing him to continue his scholarly pursuits.

This is the approximate start date when Ibn al-Haytham began writing his most influential work, the Kitāb al-Manāẓir (Book of Optics). The book was written over a period of approximately ten years and covers a wide range of topics related to optics, including vision, light, color, reflection, and refraction. The work is a seven-volume treatise on optics and is considered one of the most important contributions to the field of optics in history.

This is the approximate birth date of Abu Ali al-Hasan ibn al-Hasan ibn al-Haytham, commonly known as Ibn al-Haytham or Alhazen. He was born in Basra, Iraq, during the Buyid emirate. Alhazen was a prominent medieval scholar who made significant contributions to the principles of optics, astronomy, mathematics, and philosophy during the Islamic Golden Age. His birth marks the beginning of the life of one of the most influential scientists in history, who would later revolutionize our understanding of vision and the scientific method.