I believe those are Laser Warning Receivers which can detect whether the tank is being painted by enemy lasers and targeting systems. Whether it is a guidance laser or another tank or other asset using a laser range finder. Those sensors will detect the incoming laser and warn the crew. This will give them the opportunity to perform evasive manoeuvres and deploy any hard or soft countermeasures.
The laser dazzler on the type 99 and 99A will also use similar sensors to locate and blind the source of the incoming laser. Laze a Type 99 or Type 15 and it will employ countermeasures to prevent you from continuing target acquisition and engagement, furthermore you have also revealed your approximate location and are now vulnerable to counterattack.