diff --git a/01.curriculum/01.physics-chemistry-biology/02.Niv2/04.optics/03.optical-systems-vergence/02.optical-systems-vergence-overview/cheatsheet.en.md b/01.curriculum/01.physics-chemistry-biology/02.Niv2/04.optics/03.optical-systems-vergence/02.optical-systems-vergence-overview/cheatsheet.en.md
index f12668838..4ed55e939 100644
--- a/01.curriculum/01.physics-chemistry-biology/02.Niv2/04.optics/03.optical-systems-vergence/02.optical-systems-vergence-overview/cheatsheet.en.md
+++ b/01.curriculum/01.physics-chemistry-biology/02.Niv2/04.optics/03.optical-systems-vergence/02.optical-systems-vergence-overview/cheatsheet.en.md
@@ -71,7 +71,7 @@ Fig. 1. Direct vision : the pencils of each visible point souces intercept the p

Fig. 2a. Image vision : an optical imager (rectangle) has modified the incident pencils. Only pencils from image points enter my eyes. here the image points are real.
-
+
Fig. 2b. here the image points are virtual.
#### Optical imager and basis physical principles.