À la recherche de la vision « normale » : mesurer l'acuité visuelle au XIX^e siècle

This article aims to reconstruct and analyze debates centring on normal eye and vision standards during the second half of the 19^th century in Europe. It particularly addresses the creation of ophthalmology charts, one of the main tools for measuring visual acuity. Having briefly described the historical context in which modern eye charts were developed, we will present the better known examples of these and their characteristics. We will then analyze ophthalmologists' debates about what constitutes a normal eye and normal vision, and show the discrepancy between established definitions and clinical studies. Finally, we will consider the issue of measuring eyesight while focusing, on the one hand, on specialists' desire to create a standardized framework to measure visual acuity and, on the other hand, on the multiple hurdles that hindered achieving that goal.