Most people know of the dangers of the sun to our skin. But many do not know that too much sun can also damage the eyes.

As with skin damage, it is the ultraviolet (UV) radiation from the sun which causes problems. Some problems are short-lived, others can be permanent.

Short term problems from too much sun include:

• a ¡®gritty¡¯ feeling in the eyes;
• excessive blinking and watering;
• difficulty looking at strong lights; and
• swelling of the eyes.

More serious long-term damage includes:

• cataracts;
• sunburn of the cornea (surface of the eye), sometimes called snow blindness;
• cancer of the conjunctiva (the thin membrane covering the eye); and
• skin cancers on the eyelids.

It is relatively easy to prevent sun damage to the eyes by wearing a good pair of sunglasses and a wide-brimmed hat.

Levels of UV radiation are particularly high during summer months (3 times higher than in winter), between 10am and 3pm and at high altitudes (for example, many ski resorts).

In some situations an added dose of UV is experienced through glare, when light is reflected off a surface such as water, snow, sand or concrete. In these situations it is particularly important to wear good sunglasses.

Most sunglasses now come with an eye protection factor (EPF). This should be as near to 10 as possible. Ideally, sunglasses should have a ¡®wrap around¡¯ style or block out sideways glare. The quality of sunglasses does not necessarily relate to their darkness or cost.

Children and young adults are more vulnerable to sun-induced eye damage, so the habit of wearing good sunglasses should start early.