At a certain level of wretchedness a kind of spectral indifference takes over, and you see human beings as ghostly presences. Those closest to you are often no more than vague shadowy forms, barely distinct from life’s nebulous background and easily reabsorbed by the invisible.

[À un certain degré de misère, on est gagné par une sorte d’indifférence spectrale, et l’on voit les êtres comme des larves. Vos plus proches ne sont souvent pour vous que de vagues formes de l’ombre, à peine distinctes du fond nébuleux de la vie et facilement remêlées à l’invisible.]

Victor Hugo (1802-1885) French writer

Les Misérables, Part 4 “St. Denis,” Book 6 “Little Gavroche,” ch. 1 (4.6.1) (1862) [tr. Donougher (2013)]
    (Source)

(Source (French)). Alternate translations:

At a certain depth of misery, men are possessed by a sort of spectral indifference, and look upon their fellow beings as upon goblins. Your nearest relatives are often but vague forms of shadow for you, hardly distinct from the nebulous background of life, and easily reblended with the invisible.
[tr. Wilbour (1862)]

In a certain stage of misery people are affected by a sort of spectral indifference and regard human beings as ghosts. Your nearest relatives are often to you no more than vague forms of the shadow, hardly to be distinguished from the nebulous back-ground of life, and which easily become blended. again with the invisible.
[tr. Wraxall (1862)]

When a certain degree of misery is reached, one is overpowered with a sort of spectral indifference, and one regards human beings as though they were spectres. Your nearest relations are often no more for you than vague shadowy forms, barely outlined against a nebulous background of life and easily confounded again with the invisible.
[tr. Hapgood (1887)]

There is a level of poverty at which we are afflicted with a kind of indifference which causes all things to seem unreal: those closest to us become no more than shadows, scarcely distinguishable against the dark background of our daily life, and easily lost to view.
[tr. Denny (1976)]

At a certain depth of misery, people are possessed by a sort of spectral indifference, and look at their fellow beings as at ghosts. Your nearest relatives are often merely vague shadowy forms for you, hardly distinct from the nebulous background of life, and easily blended with the invisible.
[tr. Wilbour/Fahnestock/MacAfee (1987)]