I happened to meet a friend of mine who had complaints of itching, redness sometimes and sandy sensation. He had difficulty with light but felt his eyes were okay and he told me the only reason he just wanted to check his eyes were because he was around my hospital and just said he should give it a trial.
As a casual friend, I wanted to rush over his eyes and just do a quick examination to tell him his eyes were okay and he should stop stressing me. When I examined his eyes, I noticed his conjunctival were inflamed and eyelid a little swollen. But he kept insisting he could see near and far objects, so there's nothing wrong with his eyes. So I proceeded to use an automatic refractor on him to know his visual power. To my surprise, he had a very high astigmatism. I proceeded to do the visual analysis test for him and he could barely read 4/8 lines on the snellen chart.
To conclude the story, he needed glasses for astigmatism, eyedrop for keratoconjunctivitis sicca, pinguecula and this caused itching, redness and sandy sensation. Some eye drops were prescribed for him and glasses which he later got and now he is happy he agreed to do the test because his discomfort is no more.
The moral of this story is to never assume any medical test result unless you have done the test.