I'd really like to understand what role the lenses play in the infection occurring. Presumably an eye without a lens could also get the infection from a water source?
Even worse, it sounds like after a foothold is established, they become entrenched, and eventually no longer need the supportive bootstrap environment the contact lens initially provided. Based on the multiple relapses described in the article, it sounds as though her original infection never completely went away. So the infection can happen without contact lenses, but normal healthy eyes seem capable of fending off these attackers.
Normally, the eye is constantly flushing fluid across its surface, and I suppose the socket and inner eyelids must assist in fighting off invasive organisms, even if simply by friction and moisturization. Somehow, the artificial cap of the contact lens is different, holding the organisms in place, and offering stability and traction.
I've worn both, and whenever getting monthlies, my optometrist always told me not to get in the water with them/avoid getting water on them. In regards to dailies, it apparently shouldn't be an issue, as presumably if you get in the water with a daily, you'll probably be taking it out <12h later.
As a long-time contact lens wearer who has at time been lax with hygiene best-practice (often I drop a lens in the basin, pick it our and rinse off with saline solution), I was a little alarmed after reading what you've been through.
Can you point me towards any further background reading or references on this topic?
I knew it was very bad to shower with contacts on but I figured the daily ones would be no big deal.
Anyway, this is a good PSA.
(I may be wrong though, but I think I heard it creating a stagnant, oxygen poor enviornment that did it.)
Presumably this means you should be extremely careful while showering if you scratch your cornea.