Cleaning of upper glass cover of Epson V700

[Gilo25]

After cleaning the glass of my Epson V700 I noticed that also the glass of the upper cover is quite dirty inside. Does anybody know if this affects the image quality a much as dirt on the the lower glass and if yes is it possible to clean it following the same procedure as for the lower glass?

 

[f16sunshine]

It does not in my experience. The glass on the bed should be cleaned on both sides whenever you notice fogging or static dust accumulation.
The upper glass provides light. A bit of internal dust or haziness will not effect sharpness of scans.
Cheers!