Franciscus (Franz) Cornelius Donders FRS FRSE (27 May 1818 – 24 March 1889) was a Dutch ophthalmologist.

He was born in Tilburg, the son of Jan Franz Donders and Agnes Elizabeth Hegh.

[5] In 1848, eleven years before Charles Darwin's monumental Origin of Species was published, Donders delivered his inaugural lecture titled 'The Harmony of Animal Life, the Revelation of Laws'.

In a letter to Donders from March 1871, Darwin writes: 'It is clear to me that you were as near as possible in preceding me on the subject of Natural Selection.

[8] He is credited with invention of an impression tonometer (1862),[9] and for introduction of prismatic and cylindrical lenses for treatment of astigmatism (1860).

[12] This concept is now one of the central tenets of cognitive psychology – while mental chronometry is not a topic in itself, it is one of the most common tools used for making inferences about processes such as learning, memory, and attention.

When Donders's conducted task A, he stimulated the participant's foot in order to measure the fastest hand reaction.

Participants were made known ahead of time that they would be measuring how fast the response of their hand was (which enabled them to better sense the stimulation).

This task was also designed to measure the participants ability to detect stimuli and offer the requested response.

Donders's task C cannot be performed without intervention of stimulus discrimination occurring within the sensory and motor process.

[15] Donders founded the Nederlands Gasthuis voor Behoeftige en Minvermogende Ooglijders (in short: Ooglijdersgasthuis) – the Netherlands Hospital for Necessitous Eye-Patients in 1858.

[citation needed] Franciscus Donders spent a lot of time studying and researching biology and cognition.

He introduced subjects such as refraction, astigmatism, accommodation, ametropia, hypermetropia, aphakia, presbyopia, convergence, and quint.

[19] Of the concepts he introduced, the most important is Donder's Law,[20] which states that "the rotation of the eyeball is determined by the distance of the object from the median plane and the line of the horizon".