Question: I have just been diagnosed as having glaucoma. My mother had it too. What causes this disease?
Your eyeball contains a transparent liquid that has the consistency of half-set jelly. This liquid is produced by special cells that sit just behind the iris (the colored part of the eye). There is a slow circulation of this fluid around the eyeball and out through the pupil to the area in front of the iris. Here the fluid is absorbed back into the bloodstream.
The fluid in the eyeball is under pressure to maintain the shape of the eye and prevent distortion of the light waves entering the eye. If the pressure of the fluid increases, the light-sensitive cells inside the eye will be damaged and vision will decrease possibly to the point of blindness. Glaucoma is the disease caused by an increase in the pressure of the fluid in the eye. The most common type of glaucoma has a slow onset over many months or years. The patient may not be aware that there is anything wrong unless a routine test by a doctor detects it.
Unfortunately, the first symptom is often deteriorating vision, and by then it may be impossible to reverse the existing damage, but any further damage can be prevented by the correct treatment. There is an hereditary tendency to this type of glaucoma, and anyone who has parents with glaucoma should have their eyes checked every couple of years after the age of 35.

Question: What is color blindness?
The normal form of color blindness is an inability to differentiate between the colors red and green. In some men, other colors may be involved, but only rarely is all color vision lost with the person seeing in black and white. Color blindness is hereditary, and occurs nearly always in men.
Special cards covered in colored dots, with numbers hidden amongst the dots, are used by doctors to diagnose the condition. There is no treatment available, but most patients can live quite happily with the problem, and may have adapted so completely to the problem, that they are not aware of its existence. Those planning a to work as an electrician or commercial pilot, or in some other areas where color differentiation is vital, may not be allowed to undertake these careers.

Question: I would appreciate your opinion on the cause of a pterygium in the eyes. Some say it is glare, others sand or other foreign matter in the eyes. How is this condition caused, and how do you prevent it?
A pterygium is a fleshy overgrowth of the white part of the eye (cornea) that grows across the colored part of the eye (iris). They develop very slowly over many years, but once they are half way across the iris, they should be removed in a simple operation to avoid growth across the pupil and blindness. Pterygium are very common in Australia, but more so in the north than the south, as they are caused by recurrent mild sunburn to the cornea. The irritated tissue overgrows, and spreads across the eye.
Farmers, sailors, drivers, outdoor workers and sports people are most prone to pterygium as glare and sun exposure are the prime cause. The problem can be prevented by wearing good quality (polarized) sun glasses. A pterygium may become irritated, red and itchy at times. Simple drops available from chemists will ease this problem. Once present they will remain until removed surgically. There are no drops that will make them go away.

Question: My mother is having a vitrectomy. What sort of operation is this?
The eye contains a clear jelly-like substance called the vitreous. If this becomes discolored, the vision in that eye will be remarkably reduced, possibly to the point of blindness.
The most common cause of discoloration of the vitreous is bleeding into the eyeball. This can occur in high blood pressure, diabetes and injury. In the last few years, a very delicate operation has been devised in which the blood-stained vitreous can be removed from the eye and a new artificial substance substituted, allowing normal vision again. It is performed under a general anesthetic by an ophthalmologist (eye doctor) who has had specialist training in this procedure.