While most people think of arthritis as inflammation of the joints, increasingly, research is showing that inflammation can cause damage in unexpected ways and in unexpected places. Unfortunately, the eyes are not immune.

“The eye is like a microcosm of the entire body within a small little ball,” says Sunir J. Garg, MD, attending retina surgeon at Wills Eye Hospital in Philadelphia. Any inflammatory condition that affects collagen – the main component of connective tissue – such as rheumatoid arthritis (RA), can affect the sclera (the white of the eye) and the cornea (the lens cap), “which are basically entirely collagen,” says Dr. Garg.

Here are six eye conditions with connections to different forms of arthritis, and what you can do to protect your vision.

Keratitis Sicca (also called Dry Eye Syndrome)

What it is: The eye, for several reasons (including the consumption of certain medications or damage to tear-producing glands), is unable to maintain a healthy film of tears. This film not only lubricates the eye, it also protect they eye from foreign particles and is necessary for good vision.

What you may notice: Dryness and perhaps the feeling of having something in your eye; vision may also be blurred. “When the corneal lens start to dry out, it’s not an effective barrier,” says Dr. Garg. As a result, this condition may lead to infection and corneal scarring – which, Dr. Garg says, is like having  “a dirty windshield.”

Who it affects: Those with Sjögren’s syndrome, RA, scleroderma. “Dry eye syndrome is the most common ophthalmic manifestation of rheumatoid arthritis,” says Careen Lowder, MD, PhD, an ophthalmologist at Cleveland Clinic. “Women are nine times more commonly affected than men.”

What you can do: For eyes made dry by Sjögren’s syndrome, controlling the underlying inflammation with the medications you take for your arthritis could provide some relief, but you’ll probably also need a topical salve, artificial tears or an immunosuppressive eye drop such as cyclosporine (Restasis) to keep your eyes moist. Tear duct plugs (called punctal plugs) are another option. Running a humidifier in your bedroom may also help.

Dryness caused by medications may be relieved by switching to another medication or lowering the dose. (But never make any medication changes without consulting your doctor.) Artificial tears also can offset dryness caused by medications.

Scleritis

What it is: Inflammation of the sclera, or white part of the eye. “[Inflammatory arthritis] conditions like RA can cause the eye wall, which is the sclera, or the cornea, to become thin,” says Dr. Garg. “That’s bad because minor trauma could cause that part of the eyeball to split open,” he says.

What you may notice: Redness that doesn’t go away with the use of over-the-counter eye drops (like Visine), severe pain (described as “deep, boring eye pain” by Dr. Lowder), sensitivity to light and perhaps reduced vision

Who it affects: Those with RA, relapsing polychondritis and granulomatosis with polyangiitis (formerly known as Wegener's granulomatosis)

What you can do: In some cases, corticosteroid eye drops can control inflammation, but often the problem is too deep within the eye to be controlled locally. Scleritis is usually an indication that inflammation is out of control, not only in the eye but elsewhere in the body, so keeping your arthritis under control is critical.