Breath Flare

If your breath weapon uses fire or lightning, it is suffused with bright light. In addition to taking the normal fire or lightning damage, creatures that fail their saving throws against your breath weapon are also blinded for 1 minute. 

Creatures who lost their saving throw, can make a new Constitution saving throw against your spell DC, at the end of their turns to remove the blinded effect.

Blind or otherwise sightless creatures are not affected by the blinded condition from this spell. The modification applies to the breath prodused as part of casting.