CAT-III landings are automatic, but the pilot needs some visibility to decide if the plane is going to touch down in the landing zone. If they are totally blind they will divert.

https://en.wikipedia.org/wiki/Instrument_landing_system#ILS_...

Some commercial aircraft are equipped with automatic landing systems that allow the aircraft to land without transitioning from instruments to visual conditions for a normal landing. Such autoland operations require specialized equipment, procedures and training, and involve the aircraft, airport, and the crew. Autoland is the only way some major airports such as Paris–Charles de Gaulle Airport remain operational every day of the year. Some modern aircraft are equipped with Enhanced flight vision systems based on infrared sensors, that provide a day-like visual environment and allow operations in conditions and at airports that would otherwise not be suitable for a landing. Commercial aircraft also frequently use such equipment for takeoffs when takeoff minima are not met.