In the world of diseases and rare conditions there are cases in which a person has two parts that are normally unique. And one of them is the pupil, which is presumed unique in each eye.
A very rare pathology
The condition is called a duplex pupula, a Latin term meaning double pupil, a strange disease caused by some genetic defect or mutation that would make vision impossible.
At present, except for some mention, perhaps metaphorical, of the Chinese Emperor Liu Ch’ung and Dr. Kirby Flower Smith, there is no medical literature or genuine photographic evidence or explicit cases of people with such a condition, although some claim that they have there have been cases of people who have reported suffering from it. By contrast, there are those who argue that it is only about a true myth.
Other pathologies related to pupils that have been documented are heterochromia, a condition that causes people to have each eye of a different color, aspect that does not affect vision.
Examples of more severe pathologies are the coloboma, a disease that generates a hole in the iris with fatal consequences, or proptosis, a disease that shifts the eyes too far forward, albeit behind the veneers.
The duplex pupil involves double iris, cornea and retina and is found in an ancient legend in which a warrior has two pupils in one eye. The few and almost non-existent occasions in which it has been appointed are usually associated with a metaphorical construction, a literary figure in which, contrary to the visual incapacity it would cause in its physical form, in its interpretative form it would represent visual acuity and ability to see beyond the ordinary.
Image source: awesomefacts.quora.com
Phoneia.com (August 14, 2019). People with double pupils in their eyes, right or lie?. Recovered from https://phoneia.com/en/curiosities/people-with-double-pupils-in-their-eyes-right-or-lie/