Blind is a status debuff that incapacitates units by impairing their vision, hindering their mobility and reducing their ability to attack accurately.
When an enemy is blinded, it is shifted to a non-alerted status, making it vulnerable to the x8 stealth melee damage multiplier and stealth finishers. Blind enemies will wander about and attempt to blind fire at the general source of noise level with penalized accuracy, possibly confused by the sounds of a firing teammate. Alternatively, the enemy will use a melee attack at the last known location of its enemy.
If a damage over time status effect was applied by a melee weapon, the status effect will benefit from the x8 stealth damage multiplier while the enemy remains blinded. If applied while the enemy is blinded the damage will be even higher.
As an example, an Excalibur hits an enemy blinded by Radial Blind with a melee attack, applying a slash proc. The melee hit would be x8, then the slash proc ticks would deal 35% of that attacks base damage (after being multiplied), then x8 again.
Upon being blinded, enemies will also enter their "stunned" animation, briefly immobilizing them.
When a player is blinded, their screen will flash in bright white in a similar manner to flashbang and recover their sight after a while, however, it does not penalize the player's mobility.