As anyone who has spent five days in a dark room at a documentary film festival will attest, it can be extremely gruelling experience. Whilst death is never far from the screen, it’s those who live and endure suffering who leave the profoundest impact on me. This is definitely the case with Clay Tweel’s new documentary Gleason. Watching the emotional toll on the faces of both Steve Gleason and his wife Michel Varisco is extraordinarily moving.

Steve Gleason played as a safety in the NFL for nine years. Almost all his career was with the New Orleans Saints where he’s responsible for one of their most famous moments. A Few years after retiring, he was diagnosed with ALS (amyotrophic lateral sclerosis). He then leaned that he was going to become a father for the first time. Gleason documents the story of Steve and Michel’s battle with the disease, whilst at the same time trying to raise their son.

Whilst on the surface Gleason is a film about the effect ALS has on Steve’s life and motor functions, it’s much more than that. Through the lens of Tweel’s camera we get to see the ramifications it has on a family’s life. Whilst it’s impossible to comprehend the toll the illness takes on Steve, the same can be said for Michel. Through her we get to see what it’s like to dedicate your life to caring for someone. Gleason is a powerful and emotionally taxing documentary which gives an insight into the effect of a terminal illness has on a family.

Gleason is out in cinemas from Friday.