Ask the Chatbot Games & Quizzes ProCon History & Society Science & Tech Biographies Animals & Nature Geography & Travel Arts & Culture Money Videos
Sigmund Exner
Directory
References
Discover
Mona Lisa, oil on wood panel by Leonardo da Vinci, c. 1503-06; in the Louvre, Paris, France. 77 x 53 cm.
Why Is the Mona Lisa So Famous?
Super Typhoon Noru over the western tropical Pacific Ocean as observed by the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA Aqua satellite July 31 2017
What Is the Difference Between a Typhoon and a Super Typhoon?
Artist interpretation of a Space meteoroid impact. Meteor impact. Asteroid, End of the world, danger, destruction, dinosaur extinct, Judgement Day, Planet Earth, Doomsday Predictions, comet
10 Failed Doomsday Predictions
Mayer Amschel Rothschild (1744-1855), founder of the house of Rothschild; lithograph by Friedrich Lieder, c. 1830.
Where Do Anti-Semitic Conspiracy Theories About the Rothschild Family Come From?
Leonardo da Vinci (1452-1519), Italian Renaissance painter from Florence. Engraving by Cosomo Colombini (d. 1812) after a Leonardo self portrait. Ca. 1500.
10 Famous Artworks by Leonardo da Vinci
The Cheshire Cat is a fictional cat from Lewis Carroll's Alice's Adventures in Wonderland. (Alice in Wonderland)
11 Banned Books Through Time
Rural Irish landscape, Sligo, Ireland.
Why Is Ireland Two Countries?

Sigmund Exner

Austrian physiologist

Learn about this topic in these articles:

research on superposition eyes

  • details of the mammalian eye
    In photoreception: Image formation

    In the 1890s Austrian physiologist Sigmund Exner was the first to show that lens cylinders can be used to form images in the eye. He discovered this during his studies of the ommatidia of the horseshoe crab Limulus.

    Read More
  • details of the mammalian eye
    In photoreception: Refracting, reflecting, and parabolic optical mechanisms

    …was discovered by Austrian physiologist Sigmund Exner in the 1880s. He reasoned that the geometrical requirement for superposition was that each lens element should bend light in such a way that rays entering the element at a given angle to its axis would emerge at a similar angle on the…

    Read More