Sometimes when you first wake up, your eyes can be "dry" and tears not covering the eyeball well. The result is a very cloudy poor visual field. A few blinkings or closing the eyes and rolling them under the lids can fix this in a minute or two.

Another visual problem with your visual field, is a patch of nothing surrounded by peripheral stuff being okay. This can be a temporary blood flow problem to the retina. I had a stroke in my retina in my left eye from a blood clot in a vein ... it made things purple in the light, and a patch of black nothingness in low light/dark situations.
That is very different from "gray".

If your homocysteine levels are elevated you can get vascular problems in the retina first before it is discovered in the other parts of the body, because these vessels are small.

Uncontrolled high blood pressure will show up in the retina early, and so will elevated c-reactive protein elevations.

Another culprit is uveitis, which comes from autoimmune disease attacking the tissues inside the eye. You can look up uveitis, and learn more. Uveitis is also connected to rheumatoid arthritis and vasculitis etc.

Not everything in the eyes is MS.