Occasionally a hamster may get a sticky eye where the eyelids are fused together and older hamsters may be prone to 'sticky eyes'. This is often because a hamster may have something it its eye such as a piece of dust or it could be because the hamster's cage is placed in a draught or could be a symptom of a cold or allergy. The closed eye should be wiped with a small piece of cotton wool soaked in luke warm water. This is usually sufficient to open the eye but if not the eyelids can gently be pulled apart.

If a hamster has recurring problems with runny or sticky eyes or the eye appears cloudy the hamster could have an eye infection. This can be treated by mixing half a cup of sterile (boiled and cooled) water with a teaspoon of boric acid powder (available from a chemist or pharmacy) and using an eye dropper to bathe the eye twice or three times a day. If the hamster does not show improvement within a couple of days veterinary advice should be sought as antibiotics may help.

Although rare, hamsters can develop cataracts and the symptom is a cloudy eye. Although the cataract cannot be treated it is worth seeking veterinary confirmation as the symptoms of a treatable eye infection are sometimes similar.

Occasionally a hamster may lose an eye due to accident or illness or the eyes may be missing due to genetic deformity.

The loss of an eye or blindness does not affect the hamster too much as their eyesight is very poor and they rely mainly on smell and hearing.