Vision Problems

Allergies affecting the eye are fairly common. The most common allergies are those related to pollen, particularly when the weather is warm and dry. Allergies that affect the eyes can also be related to pet dander, cosmetics, daily chemicals and even the foods we eat.

Symptoms
Symptoms can include redness, itching, tearing, burning, stinging, and watery discharge, although they are not usually severe enough to require medical attention.

Allergies caused by the eye coming in contact with airborne allergens are:
- Hayfever conjunctivitis: a seasonal allergy that occurs when airborne allergens such as ragweed come in contact with the eyes and cause redness, watering, and itching.

- Vernal keratoconjunctivitis: also a seasonal allergy that affects outside edges of the cornea and is most often seen in children.

- Atopic keratoconjunctivitis: a chronic, ongoing allergy response affecting the outside edges of the cornea in older patients. If untreated, it can cause scarring in the eyes.

In a normal eye, light passes through the transparent lens to the retina. Once it reaches the retina, light is changed into nerve signals that are sent to the brain.

The lens must be clear for the retina to receive a sharp image. If the lens is cloudy from a cataract, the image you see will be blurred.

A cataract is a clouding of the lens in the eye that affects vision. Most cataracts are related to aging. Cataracts are very common in older people. By age 80, more than half of all Americans either have a cataract or have had cataract surgery.

A cataract can occur in either or both eyes. It cannot spread from one eye to the other.

Blepharitis, also known as granulated eyelids, is a common condition that causes inflammation of the eyelids. The condition can be difficult to manage because it tends to recur.

What causes blepharitis?
Blepharitis occurs in two forms:
Anterior blepharitis affects the outside front of the eyelid, where the eyelashes are attached. The two most common causes of anterior blepharitis are bacteria (Staphylococcus) and scalp dandruff.

Posterior blepharitis affects the inner eyelid (the moist part that makes contact with the eye) and is caused by problems with the oil (meibomian) glands in this part of the eyelid. Two skin disorders can cause this form of blepharitis: acne rosacea, which leads to red and inflamed skin, and scalp dandruff (seborrheic dermatitis).

What are the symptoms of blepharitis?
Symptoms of either form of blepharitis include a foreign body or burning sensation, excessive tearing, itching, sensitivity to light (photophobia), red and swollen eyelids, redness of the eye, blurred vision, frothy tears, dry eye, or crusting of the eyelashes on awakening.

Conjunctivitis refers to any inflammatory condition of the membrane that lines the eyelids and covers the exposed surface of the sclera. It is the most common cause of "red eye." The etiology can usually be determined by a careful history and an ocular examination, but culture is occasionally necessary to establish the diagnosis or to guide therapy. Conjunctivitis is commonly caused by bacteria and viruses. Neisseria infection should be suspected when severe, bilateral, purulent conjunctivitis is present in a sexually active adult or in a neonate three to five days postpartum. Conjunctivitis caused by Chlamydia trachomatis or Neisseria gonorrhoeae requires aggressive antibiotic therapy, but conjunctivitis due to other bacteria is usually self-limited. Chronic conjunctivitis is usually associated with blepharitis, recurrent styes or meibomianitis. Treatment requires good eyelid hygiene and the application of topical antibiotics as determined by culture. Allergic conjunctivitis is distinguished by severe itching and allergen exposure. This condition is generally treated with topical antihistamines, mast-cell stabilizers or anti-inflammatory agents.