What is a 1500m vis?
Visibiliy is the distance a which a black object of suitable dimensions, situated near the ground, can be seen and recognized when observed against a bright background;
It means the distance a which you can see a hard surface runway. With a 1500m vis you will never identify a grass runway.
What visibility do you need to land VFR?
You need to see the runway while doing your circuit. At the standard approach path angle of 3°, a 3000m visibility will allow you the see the runway (provided it's a hard surface one) at a 500 ft height. (Basic trigonometry).
Below 3000 visibility you can't see the ground ahead of you, you must look sideways, it's difficult not only to find your way, but also to keep the wings level.
At 5000m it becomes uncomfortable, but still reasonably safe, provided it does not worsen.