Science · Philosophy
Ibn al-Haytham
Optical theorist and investigator
Also known as Alhazen · Alhacen · Abū ʿAlī al-Ḥasan ibn al-Ḥasan ibn al-Haytham
Later depiction · Image credit
Who they are
Ibn al-Haytham, also known in Latin traditions as Alhazen, investigated light, vision and the relation between observation and geometrical reasoning. His Book of Optics developed an account in which seeing depends on light entering the eye. The selected translated passages show him setting out procedures for testing optical effects rather than relying only on inherited explanations.
He belongs to the timeline’s history of methods for studying perception and the physical world.
Selected contributions
Selected works
Book · c. 1021
The Optics of Ibn al-Haytham, Books I–III: On Direct Vision
Ibn al-Haytham investigates how light and sight work, using geometrical reasoning and arrangements for examining visual effects. These first three books provide direct access to his account of vision through light entering the eye.
Medieval work, commonly dated to the early eleventh century; linked English translation by A. I. Sabra published by the Warburg Institute in 1989.
Reading scope & citation
Reuses the input’s documented prior inspection: Full translation PDF downloaded; the specified methodological, experimental-arrangement and incoming-light passages inspected. Later books were not fully reviewed. No fresh full-work reread in this directory pass.
In the timeline
- Early 11th centuryIbn al-Haytham investigates light and vision
Biography sources & portrait credit
- The Optics of Ibn al-Haytham, Books I–III: On Direct Vision ↗The Warburg Institute
Portrait credit
Adolph Boÿ; engraving by Jeremias Falck. Public domain (Commons file-specific copyright declaration). Via Wikimedia Commons.
Later depiction. Cropped to 4:5, resized to 320 × 400 and converted to WebP.
Image source & identification ↗ · Public domain (Commons file-specific copyright declaration) ↗
