Derive screen brightness from the blind modifier

CHANGELOG.md

@@ -14,6 +14,7 @@
     Bug #6964: Nerasa Dralor Won't Follow
     Bug #6974: Only harmful effects are reflected
     Bug #6986: Sound magic effect does not make noise
+    Bug #6987: Set/Mod Blindness should not darken the screen
     Feature #6945: Support S3TC-compressed and BGR/BGRA NiPixelData
     Feature #6979: Add support of loading and displaying LOD assets purely based on their filename extension
 

apps/openmw/mwworld/player.cpp

@@ -563,7 +563,7 @@ namespace MWWorld
         int blind = 0;
         const auto& magicEffects = playerClass.getCreatureStats(player).getMagicEffects();
         if (!world->getGodModeState())
-            blind = static_cast<int>(magicEffects.get(ESM::MagicEffect::Blind).getMagnitude());
+            blind = static_cast<int>(magicEffects.get(ESM::MagicEffect::Blind).getModifier());
         windowMgr->setBlindness(std::clamp(blind, 0, 100));
 
         int nightEye = static_cast<int>(magicEffects.get(ESM::MagicEffect::NightEye).getMagnitude());