It's important to understand that realism is an "interpretation" stage. Before we get there, we selectively _attend_ to and process stimuli. It is at this attention stage, and usually for (personally) emotional stimuli that depression can affect the things which we "see" (attend to).

Biases in attention and interpretation in adolescents with varying levels of anxiety and depression https://www.tandfonline.com/doi/full/10.1080/02699931.2017.1...