The eye is constantly exposed to a variety of pathogens, but infections occur when the normal defences of the eye are compromised. Eye infections can occur in different parts of the eye and can affect just ons of both. The source of the infection may be local, e.g. from the surrounding eyelids, or remote, e.g. from nasal sinuses. Eye infections can also be a result of trauma, eye surgery, contact lens wear, immune deficiencies, or other diseases resulting in bacterial growth or other micro-organisms.
Inflammation is your own body’s response to injury, infection or irritation. Inflammation can occur in response to normal harmless substances, like grass or pollen. Other common causes can be a deficiency of vitamin A, improper contact lens use, overuse of prescription and over-the-counter eye drops and cosmetics.
The immune system may also trigger inflammation in response to the body’s own tissue, called an autoimmune reaction. It is important to note that eye inflammation can be a sign of a serious condition, such as orbital cellulitis, corneal abrasions or an aphylaclic reactions.
The crystalline lens sits behind the coloured part of the eye (iris), and cannot usually be directly seen with the naked eye. The normal crystalline lens is transparent and any congenital or acquired opacity (clouding) in the lens or it’s substance, irrespective of the effect on vision, is a cataract.
Cataracts typically progress slowly to cause vision loss and sometimes has the potential of blinding if untreated.
Glaucoma is an eye disorder in which the optic nerve suffers damage, permanently damaging vision in the affected eye(s) and progressing to complete blindness it untreated.
The most important risk factor is an increase pressure (IOP) in the eye, seconding to a reduced aqueous outflow in the eye.
Macular degeneration is a progressive eye condition in which part of the retina, called the macula, is damaged, resulting in lost central vision. Central vision allows us to see the fine details when we look directly at something, such as doing close work (sewing), recognizing faces and reading
Systemic Diseases and the Eye
Systemic diseases are diseases that involve many organs or the whole body. Many of these diseases also affect the eyes. In fact, an eye exam sometimes leads to the first diagnosis of a systemic disease.
The eye may be involved in these diseases, among others:
- Diabetes mellitus: An imbalance in blood glucose levels
- Grave’s disease: A thyroid disorder, most often in woman which can cause a swelling in the front of the neck and protruding eyes.
- Sarcoidosis: A disease that mainly affects the lungs, brain, joints and eyes.
- Acquired immunodeficiency syndrome (AIDS): A life-threatening disease caused by a virus that cripples the body’s immune defences.
- Systemic lupus erythematosus: A connective tissue disorder that can block circulation throughout the body.
- Multible sclerosis: A disease that damages nerve coverings, causing weakness, coordination and speech disorders.
- Double vision