Dry eye can easily be mistaken for other conditions, such as conjunctivitis, so it may be advisable to ask your optician to check your eyes. Diagnosis of dry eye can be done with a dye to colour the dry patches.
There are two main dyes used for diagnosis.
This is a harmless yellow-orange dye that can show the eye specialist how long it takes for dry eye patches to appear. The specialist will put a couple of drops into your eye and will ask you to blink a few times. Then you will need to keep your eyes open without blinking to see when the dry patches form.
A non-toxic dye, known as Lissamine Green, is diluted with saline and dropped on the surface of your eye with a paper strip. The distinctive green colour of the dye allows the specialist to see early damage to the surface of the eye.