This is a Movie Health Community warning. It is intended to inform people of potential health hazards in movies, and does not reflect the quality of the film itself.
Dunkirk has one scene where a light is going out, and flickers slowly as it does.
There are several scenes of air combat, during which we follow fighter planes through complex maneuvers at extreme heights. There are also extensive scenes on watercraft which will most likely trigger any issues with seasickness. Handheld camera work is also used, but sparingly.
Flashing Lights: 3/10. Motion Sickness: 9/10.
ADDITIONAL NOTE: This is a very immersive and intense war film. Not recommended for anyone with combat-induced PTSD, as there are very loud and sudden gunshots and explosions throughout.