The lids consist of movable tissue. Inside they are coated by a smooth, delicate tissue-membrane which, if traced up and down, forms a fold coming back on itself and then enveloping the eye, but stopping at the edge of the cornea. This fine membrane is called the conjunctiva. Thus the inside of the lid and the surface of the eye are in direct contact, more so when the lids are closed and the cornea itself is covered. Sometimes this membrane becomes subject to a mild infection, of a non-specific type, and the result is conjunctivitis. This is not usually a serious condition, and is easily treated either with drops or by bathing the eye in a prepared solution. The symptoms are irritability, discharge, redness, particularly along the top edge of the lower lid, and occasionally swelling. Most people will experience conjunctivitis at least once in their lives. Some have more than one attack each year. People who wear contact lenses are more prone, since the daily routine of placing lenses on the eye offers a greater opportunity for an infective organism or irritant chemical to reach the eye. Read the rest of this entry »
At the beginning of this century the most prominent cause of blindness was infections of the eye. The eye is exposed externally to infections because of the very delicate skin-lining of the lids and sensitive outer membrane of the eye itself. Other tissue areas of equal susceptibility to infection are the nose, mouth and genitalia. It is even possible for all these orifices to be infected by the same organism.
Since the the availability of antibiotics has drastically reduced the incidence of chronic consequences following an infection. Many serious infections, provided they are treated quickly, no longer inflict severe damage. Read the rest of this entry »
The eye has its natural protective mechanisms. The lids, for example, protect the front of the eye from dust, wind and objects coming towards the face. They also protect the eye from excessive light. The eye itself is set in its bony cavity: the orbit. In the orbit there are some soft fatty tissues which act as a cushion, permitting the eye to sustain a light blow without injury. Nevertheless the eyes are vulnerable. The eye will be injured, often severely, by fast-flying hard objects, and also by some gases and solutions. It is easy to incapacitate a human being, either temporarily or permanently, by spraying irritant solutions onto the face, and such methods have been widely used by criminals, police and the armed services. Read the rest of this entry »
