Related Rule
Canada
Practice Relating to Rule 86. Blinding Laser Weapons
Section B. Laser systems incidentally causing blindness
Canada’s LOAC Manual (1999) states:
Blinding as an incidental or collateral effect of the legitimate military employment of laser systems is not covered by the prohibition [on blinding laser weapons]. For example, the legitimate use of a laser targeting system in a tank is lawful even if one of its collateral effects may be to cause blindness. However, such a laser targeting system could not be deliberately used to blind enemy combatants. 
Canada, The Law of Armed Conflict at the Operational and Tactical Level, Office of the Judge Advocate General, 1999, p. 5-3, § 30.
Canada’s LOAC Manual (2001) states in its chapter entitled “Restrictions on the use of weapons”:
Blinding as an incidental or collateral effect of the legitimate military employment of laser systems is not covered by the prohibition [on blinding laser weapons]. For example, the legitimate use of a laser targeting system in a tank is lawful even if one of its collateral effects may be to cause blindness. However, such a laser targeting system could not be deliberately used to blind enemy combatants. 
Canada, The Law of Armed Conflict at the Operational and Tactical Levels, Office of the Judge Advocate General, 13 August 2001, § 519.3.