suite

01.curriculum/01.physics-chemistry-biology/02.Niv2/04.optics/04.use-of-basic-optical-elements/01.plane-refracting-surface/02.plane-refracting-surface-overview/cheatsheet.en.md

@@ -89,7 +89,7 @@ Ray tracing study of a **spherical refracting surface** :
 
 ![](dioptre-spherique-non-stigmatique-1.png)<br>
 
-* **If we limit the opening** of the spherical refracting surface so that only the rays 
+* **If we limit the aperture** of the spherical refracting surface so that only the rays 
 meeting the surface near the vertex are refracted through the surface.
 
 ![](dioptre-spherique-non-stigmatique-2.png)<br>