When zooming in and out from your model you may also see the points changing size in comparison to the rest of the model, this is due to the command PDSIZE.
When set to 0 this will mean your points will take up 5% of the screen at all times.
If you’d like to turn this off, set the PDSIZE to anything higher than 0.
To then change the size after this first time, run the command again and change the value but after use the command REGEN to activate this change.
The measurement of this follows the measurements of the file so PDSIZE = 50 would be 50 units of the file and works using this number as the diameter of the point, whether that's a circle, square or X.