As the path of light is bent by dark matter, our view of any stellar object on the other side is warped in an effect called gravitational lensing.

Light follows the curvature of spacetime.

In General Relativity, mass bends spacetime.

Hence when it passes in the region of a very massive object – like a large galaxy cluster, light is subsequently bent.

This means that the light from a distant object, like a galaxy, on the other side of it, will be bent towards an observer’s eye, just like an ordinary lens.

Since we normally assume that light always moves at a constant speed, gravitational lensing changes the direction of the velocity of the light, but not its magnitude.

Light rays are the boundary between the future, the spacetime, and the past regions.

The gravitational attraction can be viewed as the motion of undisturbed objects in a background curved geometry, or alternatively as the response of objects to a force in a flat geometry.

Looking through dark matter is almost like observing an object moving behind a pane of frosted glass…  The objects you do see appear a little distorted and warped…