My particles are not visible in the distance

Hey guys! I made a GPU particle system of a star field. Unfortunately can’t show you for NDA reasons, so hopefully I’ll be able to describe the issue.

I need a lot of stars to be seen at once, some in the front, some in the back, but I need them to be seen. At the moment, they can only be seen in the front, they almost look like they are only spawning from certain distance to a certain distance. If I turn off Real time rendering, I can see there’s so many stars, but it looks bad. In real time, they look good, but they can’t be seen. Any ideas please?