What happens to your cornea
Four things, in order. None of them hurt at the time — your eye is numbed with drops throughout.
- Riboflavin soaks in — vitamin B2 drops, given every few minutes until the cornea is saturated
- UVA light activates it — a precise, measured dose; far less than an hour in Karachi sunshine delivers to your skin
- New bonds form — between the collagen fibres that had been slipping
- The cornea stiffens — measurably, and permanently in the great majority of eyes