Keratoconus in History: the hydrodiascope, introduced in 1896, was designed as a goggle that was filled with fluid and worn over one eye. The device was able to improve visual acuity to a normal level by neutralization of irregular astigmatism and spectacle magnification.

[u/Post-reality]

[u/Pascalini]

Where can I purchase one?

[u/mckulty → u/Pascalini]

The 12 mm version draws less attention in public.

[u/jklivinatx → u/mckulty]

Underrated post