viewer
//ˈvjuːər//
Noun
viewerSingular
viewersPlural
1
A person who watches something, especially television or a video.
The show attracts millions of viewers every week.
2
A person who looks at or inspects something.
The painting attracts many viewers at the museum.
3
A device used for looking at photographic slides, film, or other visual material.
I used a slide viewer to look at my old vacation photos.