A novel optical screen comprises, as its viewing surface, a hard, abrasion-resistant coating having a rough, glare-reducing surface and composed of a lithium silicate material. The screen may be prepared by a novel method comprising: (a) warming the surface of a glass support to about 30* to 100* C., (b) coating the warm surface with an aqueous solution containing about 1 to 10 weight percent of a lithium-stabilized silica sol, (c) drying the coating, and then (d) heating the dry coating at about 150* C. to 450* C.