I create some glass material for Eevee. When the camera is close to glasses, then everything is rendered normally . But if I move the camera away, then the detail decreases in the glasses. They become low res . How to fix that? Material https://drive.google.com/open?id=1tv0vuTxDTA0mOjbVgbrudOdyOlAjzYNT
Pixelation is visible on any of your glass cup object. Not only on far one from camera. The issue is just more visible on smaller cup than big one. So it has nothing to do with camera distance, but aliasing. Probably cost of eevee speed.
With Glass node IOR to 1 (or above, ussually 1.43 is used) pixelation is gone.
You can try to set Film > Filter Size > 3 in Render Properties. Filter Size cares about aliasing, but in price of loos of sharpness (render became softer). Blender manual.
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