diff --git a/gamedir/Data-1.13/Ja2_Options.INI b/gamedir/Data-1.13/Ja2_Options.INI
index a5cdbb6e7..bad5c9b1e 100644
--- a/gamedir/Data-1.13/Ja2_Options.INI
+++ b/gamedir/Data-1.13/Ja2_Options.INI
@@ -451,6 +451,8 @@ BASE_SIGHT_RANGE = 13
 
 ; Controls how rain affects visual distance 
 ; Range: 0-100%
+; 0% - no decrease
+; 100% - max
 VISUAL_DISTANCE_DECREASE_PER_RAIN_INTENSITY = 30
 
 ; Enable/disable militia command on tactical map