Good soalr eclipse viewers offer just enough magnification to make eclipse viewing interesting while complying with all the relevant ISO safety standards.

Good eclipse glasses reduce the sun’s brightness by a factor of about 500,000, making it appear about as bright as the full moon.

The best eclipse viewers: Celestron EclipSmart 2x Power Viewers (ISO certified, inexpensive) 

The best binocular filters: DayStar Universal Lens Filter ULF-50-2

The best paper glasses: American Paper Optics Eclipse Glasses (no magnification)

The best fits over eyeglasses: American Paper Optics Eclipser HD Safe Solar Glasses (expensive than paper shades)

The best fits for your 50mm camera lens: DayStar Universal Lens Filter ULF-50 (cheap)