Perhaps it is an artifact from some coatings on the window(?) or prehaps its just the nature of the window material.

There were anti-glare and anti-reflection coatings on the windows of the LM and also of the CM. These are not dissimilar from optical coatings on photographic lenses. When you see external photographs of the LM on the lunar surface, the image of the surface reflected bluishly in the LM windows is the effect of the anti-glare coating. Without the coating the image would be much brighter, and not blue.

However, this isn't the same phenomenon which causes the blue-tinted glow seen from within the spacecraft, illustrated in the photograph above. That is scattering caused by the glass itself and by contaminants on the glass. It is possible that the coatings contribute to this effect, but not likely.

We generally don't see this degree of scattering through windows on earth because it's frequently drowned out by directly transmitted light from the atmospheric scatter -- i.e., it's scattered by the atmosphere but passes directly through the glass.

The angle at which the light strikes the glass and the angle from which it is viewed inside the cockpit determine how visible this effect is.