Eye diseases that require immediate care are very rare. Actually only one situation is real emergency: if the vision disappears in one eye as if the light was switched off. The treatment should be started as soon as possible. The cause of the sudden disappearance of vision is disturbance in the circulation of the eye, the retinal artery is blocked. The treatment should be started within an hour at the latest, otherwise the retinal cells would be too badly damaged and could not recover.

If you need an interpreter in the emergency situation, it is important to inform the hospital that you need an interpreter. The clinic may not have interpreters for emergency patients and a young doctor may feel confused if exposed suddenly to an emergency situation with communication difficulties.

All accidents should be taken care of immediately but there is usually no great hurry. It is more important that the patient is transported calmly with both eyes covered. If the patient is a young child only the traumatized eye should be covered.

If an eye becomes reddish, painful and vision becomes blurred, the reason for the symptoms should be found out within a day. It may be iritis, glaucoma, or corneal or optic nerve inflammation.

Small flashes of light, that appear in a certain part of the peripheral visual field when one enters a darker room, may be a symptom of retinal detachment and should be checked.

Eyes are moved by six eye muscles. If one of the muscles is paralysed the patient develops double vision, diplopia. The two images are further away from each other when the person looks in the direction of the paralysed muscle's action. If the head is turned to compensate for the loss of action, double vision disappears. It is easier to get rid of the disturbing double image by covering one eye. If there are no other symptoms there is no emergency situation. Double vision is usually caused by circulatory disturbance in the nerve that innervates the muscle. The family doctor can take care of the basic examination and consults an ophthalmologist if needed.

Sometimes a small blood vessel bleeds on the surface of the eye. The white part of the eye may become blood red. Bleeding under the conjunctiva, sugillatio, looks frightening but is quite harmless. It is comparable to a bruish in the skin, on the eye it only looks worse.

Bleeding under conjunctiva or sugillatio disturbs the family and neighours more than the person him- or herself. It requires no treatment and disappears in a few days.

The eye lids may become so swollen that it is impossible to open the eye or the conjunctiva hangs outside the eye lids. First aid is to fill a small plastic bag with crushed ice, wrap it in a towel and place it over the itching and burning eyes. Soothing eye drops can be obtained over the counter in most places. The symptoms usually disappear in a few hours. The reason for the lid swelling may be an allergic or toxic reaction. If only the right eye is swollen and the person is right handed the reason often is chemical, e.g. plant juice.