Keratitis is the inflammation of the cornea, the clear front surface of the eye that you would place a contact lens onto. This is generally much more serious than conjunctivitis and usually involves pain and light sensitivity. It can be potentially sight threatening. Keratitis includes ulcers which can be bacterial or even due to herpes simplex, the virus that causes cold sores on your lips.
Keratitis is often associated with contact lens wear, especially sleeping with lenses in that aren’t meant to be slept with or from swimming with them in or using tap water to rinse them instead of the proper disinfecting solutions.
Uveitis is inflammation inside the eyes, and like keratitis, is very much associated with pain, light sensitivity and red eyes. Treatment is usually steroid eye drops for around 2 months. Quite often there is no known cause, but in recurrent attacks there can be an association with systemic diseases such as ankylosing spondylitis, psoriatic arthritis, reactive arthritis, and Crohn’s disease. Sometimes it can be rarely due to infections such as tuberculosis, toxoplasmosis and even syphilis.