A thermoplastic resin composition comprises about 100 parts by weight of a polycarbonate resin; and about 0.5 parts by weight to about 3 parts by weight of polystyrene-poly(methyl methacrylate) copolymer particles, wherein the polystyrene-poly(methyl methacrylate) copolymer particles include about 41 wt % to about 59 wt % of polystyrene and about 41 wt % to about 59 wt % of poly(methyl methacrylate) and have an average particle diameter of about 3 μm to about 9 μm and a coefficient of variation (CV) of about 20% to about 40%. The thermoplastic resin composition can have good properties in terms of light transmission, light diffusion and balance therebetween.