The condition and the treatment(s)
Dry eye disease (also called dry eye syndrome and sometimes 'keratitis') is a common condition in which a person's eyes don't make enough tears, or their tears evaporate too quickly. This leads to the eyes drying out and becoming red and swollen.
Severe dry eye disease can cause blurred vision and a feeling of grittiness in the eye. If untreated, it can sometimes cause blindness.
It is most often treated with artificial tears (also called tear substitutes) and drugs to reduce any swelling.
NHS Choices (www.nhs.uk) may be a good place to find out more.