Is the Universe Acting a Lens?

If the universe is curved then photons, for example, that from really far apart, will curve towards each other. And so those lumps will appear to be slightly bigger than they actually are. In our simulations we can see all look, the spots get bigger. Then we can dial down the curvature to negative as to overlook the spots getting smaller. We go out and we look in the actual universe, and we say, which of these best describes what we syou know it is the universe look like it's flat or its curved one way or the other.