Ibn Al Haytham Optics II – Life and Achievements

Ibn al Haytham was born in Basra (Iraq). He studied and commented on the works of Aristotle, Euclid, Archimedes, and Ptolemy and devoted his life to the study of physics. He would have held the position of vizier in the government of Basra. Then, he lived in Cairo during the time of the Fatimid Caliph Al Hakim (1010). He designed a hydraulic project to damp the Nile; this project would probably have been rejected by the Caliph. He died in Cairo, devoting himself entirely to his work which includes (according to bibliographer Al-Qifti) more than 100 titles, including 50% in mathematics, 14 in optics, 23 in astronomy, 2 in philosophy, 2 astrology, 3 in static and hydrostatic and 4 on diverse themes. Known in Europe under his Latinized name Alhazen (Alhacen), he was rediscovered thanks to Gustav Wiedemann (1852, 1928), Abdelhamid I. Sabra (1924-2013) who carried a first critical edition of the Arabic first 3 books and the translation of these books in English and Roshdi Rashed who wrote many books on the history of Arab sciences. The identity of Alhazen has also been demonstrated by G. Caussin de Perceval in his “Memoir on the optical Ptolemy” of the Royal Institute of France (Academy of Inscriptions and Belles Lettres, vol. 6, p, 20- 23 (1822)). The name of Alhazen appeared in the Larousse dictionary of the twentieth century in six volumes in the supplement of second edition (1928).

Portrait of Ibn  Al Haytham. Credit: Prof. Zargar Zahoor

Portrait of Ibn
Al Haytham. Credit: Prof. Zargar Zahoor


Ibn al Haytham has undertaken the reform of optics as a builder who makes a masterpiece for posterity. He is one of those geniuses that humankind has from time to time with several centuries of interval that illuminate further and ever. His reasoning was clear; he rejected the Greek theories, suggested a new paradigm and explained the reflection and refraction. Light is material and it propagates with a high velocity. Refraction is due to the change of light velocity when it changes the medium of propagation. The shock of light with matter creates reflection. Ibn al Haytham explained the refraction on the basis of the principle that the velocity of light is affected by the density of the medium. He took into account two factors in the movement of light, one vertical and perpendicular to the surface between the two media, and with a constant velocity, and the other horizontal, parallel to the surface provided with a variable velocity. His theory is very modern in design, the approach is scientific.

This illustrious scientist has really laid the foundations of modern optics with its experimental approach to light propagation. He has, in fact, introduced experimentation in Physics.

What was optics in Greek times?

Optics was the science of vision and that of the geometer. The purpose of the Euclid’s and Ptolemy’s optics was the vision and not light. Light is necessary for vision but it is not in any in case a physical entity to which the visual organ is sensitive.

What becomes of the optics with Ibn al Haytham?

Optics became the science of light. Ibn al Haytham developed a theory of light, its propagation and its effects as an agent. He clarified the difference between the propagation of light and the vision, developed a mathematical theory on the model of a solid ball movement thrown against an obstacle associated with a geometric approach (the corpuscular approach before time!). For him, optics consisted of two parts: on one side the theory of vision and physiology of the eye and the associated psychological perception; and on the other side, the theory of light with geometrical optics and physical optics. For Ibn al Haytham, the eye is an optical instrument and light is an independent physical entity of visual sensation.

Ibn al-Haytham can be regarded as the first to introduce the “scientific method” which was very similar to the modern scientific method and included the following procedures:

  • Observation
  • Definition of the problem
  • Formulation of a hypothesis
  • Hypothesis testing through experimentation
  • Analysis of the results of experiments
  • Data interpretation and formulation of conclusions
  • Publication of results


  1.  R. Rashed, ‘Histoire des sciences arabes, tome1, 2 et 3’, Ed. du Seuil (1997).
  2.  R. Rashed, ‘L’optique et la cataoptrique’, Volume 1, Ed. E. J. Brill (1997).
  3.  R. Rashed, ‘Optique et mathématique’, Ed. Variorum (1992).
  4.  R. Rashed, “A Pioneer in Anaclastics—Ibn Sahl on Burning Mirrors and Lenses,” ISIS 81, 464-91 (1990).
  5.  R. Rashed, ‘Problems of the transmission of greek scientific thought into arabic : examples from mathematics and optics’, 199-209, Science History Publications Ltd (1989).
  6.  R. Rashed, ‘Analysis and synthesis according to Ibn al Haytham’, C. C. Gould and R. S. Cohen (eds.) Artifacts, Representations and Social Practice, 121-140, Kluwer Academic Publishers, Printed in the Netherlands (1994).
  7.  G. Simon, ‘Archéologie de la vision : l’optique, le corps, la peinture’, Ed. du Seuil (2003).
  8.  B. Steffens, ‘Ibn al Haytham, First scientist’, Ed. Morgan Reynolds (2007).
  9.  D. C. Lindberg, “Medieval Islamic Achievement in Optics”, Optics and Photonics News, 31-35, July (2003).
  10.  A. Kwan, J. Dudley and E. Lantz, “Who really discovered Snell’s law?”, Physics World L 2002
  11.  H. R. Turner, ‘Science in Medieval Islam’, University of Texas Press (1995).
  12.  B. Maitte, “La Lumière”, Ed; du Seuil (1981).
  13.  V. Ronchi, ‘Histoire de la lumière’, Ed. Jacques Gabay (1996).
  14.  R. G. Morrison, ‘The enterprise of Science in Islam’, Edited by Jan P. Hogendijk and A. I. Sabra, Cambridge, MA/ London : MIT Press (2003).
  15.  V. Gonzalez, ‘Universality and Modernity of Ibn al haytham’s Thought and Science’, The Institure of Ismaili Studies (2002).
  16.  Filali-Ansary, ‘Islam’s Reformist Tradition’, The Institute of Ismaili Studies (2004).
  17.  R. Gorini, ‘Al Haytham the man of experience. First steps in the science of vision’, 53-55, JISHIM (2003).
  18.   J. J. O’Connor and E. F. Robertson, ‘Abu Ali al Hassan Ibn al Haytham’, Mac Tutor History of Mathematics (1999). (www-history.mcs.st-andrews.ac.uk).
  19.   Herausgegeben von Fuat Sezgin, “Wissenschaft und Technik im Islam“, Institut für Geschichte der Arabisch-Islamischen Wissenschaften an der Johann Wolfgang Goethe-Universität, Frankfurt am Main (2003).
  20.   Dominique Raynaud, ‘Ibn al-Haytham sur la vision binoculaire: un précurseur de l’optique physiologique’, Arabic Science and Philosophy, 2003, 13: 79-99.
  21.   Charles M. Falco, ‘Ibn al-Haytham and the Origins of Computerized Image Analysis’
  22.   Sameen Ahmed Khan, ‘Arab Origins of the Discovery of the Refraction of Light’, OPN October 2007.
  23.   Charles M. Falco, Aimée L. Weintz Allen, ‘Ibn al-Haytham’s Contributions to Optics, Art, and Visual Literacy’, PainteOd pticsS ymposi, Florence, September 7 -9, 2008.
  24.   Anne-Valérie Dulac, ‘Shakespeare et l’optique arabe’, Actes des congrès de la Société française Shakespeare (Shakespeare et l’Orient) 27 (2009).
  25.   Archimedes and the Burning Mirror, http://www.unmuseum.org/burning_mirror.htm

More posts on Ibn Al Haytham and Arabic Optics Series

Ibn Al Haytham Optics I – Introduction and Optics before Ibn Al Haytham

boudriouaAzzedine Boudrioua is a full Professor at the University Paris 13. He is leading Organic Photonics and Nanostructures group of Laboratoire de Physique des Lasers (LPL). He is currently developing activities in the field of nanophotonics as well as nonlinear optics. He was involved in the organization of several conferences. He participates to several national and international scientific committees and expert panels. He is a member of the French Optical Society board and he is involved in several national and international projects and he is leading some of them. More recently he also concentrates on the history of medieval optics. He is Coordinator of Ibn al Haytham International Working Group

2 thoughts on “Ibn Al Haytham Optics II – Life and Achievements

  1. Nice and informative article.

    A related article:

    Sameen Ahmed Khan,
    Medieval Islamic achievements in optics,
    Il Nuovo Saggiatore, Volume 31, No. 1-2, pp. 36-45 (January-February 2015).

    With warm regards + best wishes

    Sameen Ahmed KHAN
    Professor of Physics
    Engineering Department
    Salalah College of Technology,
    Salalah, Sultanate of OMAN.

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