'I put my contact lenses in - and 12 hours later, I was BLIND.' SUSANNAH JOWITT had been wearing lenses for 40 years… until one simple mistake almost cost her her sight ⊕

One morning I pulled a contact lens case out of my bag, swiped out each lens - the reusable kind - and bunged them into each eye as casually as I had done since I first got contacts aged 16...