Most probably full of finger prints and smudges!
Try the Sample Of Kimtech Touchscreen Cleaning Wipes to get rid of them.
They will not scratch glass surface.
To request a Sample Of Touchscreen Cleaning Wipes
Click for US residents.
This is a US freebie.
Please note that we do not supply the Free sample. We only publish the offer from the company.
If the offer is EXPIRED , you might want to check the Freebies below