Are there any correlations between people who wear contacts and have keratoconus? I'm asking, because handling contacts effectively requires you to rub the eyes a little every time you take the contacts out. Or is that kind of deformation not enough?
(empirical, non scientific opinion): usually, wearing contact lenses tends to prevent vigorous eye rubbing, during the day. Also, people with sensitive, itchy eyes tend to avoid contact lenses: this is a two-way relationship. Nefarious eye rubbing is usually related to a daily, compulsory "habit", involving a vigorous pressure on the eye using the knuckles or the side of the index, also frequently present while sleeping.