Assertion: lens's shape | /r/HasProperty | devised by descartes
Facets:
Source sentences:
text: Early attempts at making aspheric lenses to correct spherical aberration were made by René Descartes in the 1620s, and by Christiaan Huygens in the 1670s; the cross-section of the shape devised by Descartes for this purpose is known as a Cartesian oval.