According to Alves, inferior systems lead to ghosting and blurring, leaving audiences with headaches. These include vision problems such as ghosting, halos, starbursts, double-vision, and dry-eye syndrome. Digital SDTV eliminates the ghosting and noisy images associated with analog systems. The polarization system has better color fidelity and less ghosting than the anaglyph system. Outside signals entering the cable can cause unwanted noise and picture ghosting. Ghosting and darkening of the images may appear in some scenes. As such, interlaced video may exhibit ghosting or combing artifacts when watched on a computer. The CRT display also suffered from a low refresh rate and heavy ghosting. Such shadows are termed "ghost images", and the effect is termed "ghosting". Jagged edges as well as some ghosting of interface elements are reported to occur. PAL-NTSC conversion artifacts also include softness and ghosting. In analog video or TV systems, this causes ghosting in the image. When the effect is particularly bad, "ghost images" are seen, called "ghosting". The ghosting and ring around problems have recurred on the more modern radars. Windows Vista also supports "ghosting" of online files and folders.