So unpleasant or distressing to see that one cannot bear to look; unbearable to watch.
事故現場の様子はあまりに悲惨で見るに堪えなかった。
The scene at the accident was so tragic that it was unbearable to look at.
あの映画の一部は表現が過激で、見るに堪えないと感じた人もいる。
Some people felt parts of that film were so extreme they couldn't bear to watch.
部屋の散らかりようは見るに堪えないほどだったので片付けを始めた。
The room was in such a mess that it was unbearable to look at, so I started cleaning.