Eye Disease Explanations

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1. Conjunctivitis

Conjunctivitis literally translates into inflammation of the conjunctiva. Conjunctiva is the layer of tissue that covers the sclera (white part of the eye) and the inner eyelids. It is epithelial tissue that secretes lubricating mucus and tears (to a much lesser extent than the lacrimal glands). Inflammation is a process by which an immune response is mounted, often translating into increased blood flow to the area (to bring more immune cells), swelling from edema, redness in appearance, heat and often pain. Inflammation is usually a sign that an infection or some other threat that causes the immune system to activate and react is present.

As a result, conjunctivitis often occurs when the conjunctiva, which does serve as a barrier to infectious agents, detects the presence of a pathogen and wishes to remove it. Keep in mind that this could be for a number of reasons: bacterial infections, viral infections, even allergies can cause conjunctivitis. Irritation alone can be enough for certain aspects of the immune system to react and cause inflammation, and so irritation of the eyes (specifically, in this case, the conjunctiva) by chemicals (e.g. if you were working with bathroom cleaner and rubbed your eyes), you could also get conjunctivitis.

It normally appears as redness, swelling and occasionally pain, depending on severity. The eye often reacts by producing more tears to flush out the invading substance, much akin to when it detects a foreign object is stuck on the eye. Bacterial infections causing conjunctivitis might also be associated, ...