Judging by the Keratoconus sub-reddit [reddit], there are probably plenty of undiagnosed people out there - maybe not even noticing their eye-sight is constrained.
Keratoconus is a disorder which describes the middle cornea to thin, bulge outward, and form a rounded cone shape, causing plenty of issues - most noticeably double vision, astigmatism and red dry eyes. According to Wikipedia it affects about 1 in 2000 people.
The disease can progress in irregular speed and so far I understand only Corneal Cross-Linking (CXL) OPs showed positive results in reducing/stopping the progression, but it's not side-effect free and at least for me the CXL was a rather traumatic experience and it renders your eye-sight pretty bad for the next weeks and even a year after I could still notice difference in my vision.
Having a Eye Drop instead of CXL would mean more people could be cured and the cure would be way less invasive. So this news is a big deal for everyone who's affected and didn't had CXL yet.
If you notice double vision on high-contrast sharp images such as white text on black background, chances are you are affected. [0], [1]
[0]: https://en.wikipedia.org/wiki/File:Kc_simulation.jpg
[1]: https://en.wikipedia.org/wiki/File:Kc_simulation2.png
[reddit]: https://www.reddit.com/r/Keratoconus/