Eye diseases are classified according to the organ affected and are divided into diseases of the eyelids, cornea, retina, lacrimal apparatus, conjunctiva, iris and lens. The most common refractive defects are: myopia, hyperopia, presbyopia and astigmatism. The perfectly with myopia see nearby objects, but have difficulty focusing on distant objects.

The sighted have problems with both near objects and distant objects, with astigmatism do not have the right perception of depth, while the sighted have difficulty to focus quickly.

Also very frequent diseases of the conjunctiva: conjunctivitis is the most common infections affecting the eye. The conjunctivitis can be bacterial, viral or allergic. The eye disease symptoms are hyperemia (red eyes, bloodshot), lacrimal secretions, blurred surface of the pupil, the formation of follicles or growths on the sides of the conjunctiva. When the inflammation is more aggressive bacterial organisms may lead to the formation of follicles, ulcers and granulomas.

The pinguecola is instead caused by inadequate nutrition of the blood vessels of the eye and overexposure to weather occurs with the formation of an excrescence yellowish nasal side of the cornea. It is a disease that primarily affects the elderly and surgical care.

Glaucoma is a condition affecting the optic nerve. When the eye suffers from glaucoma certain nerve cells die, causing visual disorders: the view is disturbed by dark spots (scotomas) that increase to almost total blindness if the disease is not limited. Even with appropriate treatment glaucoma will always remain, but can be kept under control. Advanced age, myopia, diabetes and inheritance are among the most frequent causes of an outbreak of this disease.

A cataract is nell'opacizzazione instead of the lens, which leads to progressive vision loss. It is more common with age, but there are also cases of cataracts at a younger age. The view is blurred perhé the lens filters may well fail to light that reaches the retina uniformly.

Diseases of the eyelids are varied. One of the most common is the sty, an abscess that was born inside or outside edge of the eyelid, caused by infection of the glands surrounding curable with compresses, eye drops, ointments, and in severe cases, a small incision.

Very common is also the blepharospasm, which consists of involuntary contractions of the orbicularis muscle and causes flicker of the eyelid. It is generally caused by stress and requires no cure, treatment of simple muscle contractions.

Blepharitis is an inflammation that occurs with hand peeling of the skin that surrounds the eye, oily debris and possible swelling, redness around the eyes. This type of disease can be caused by untreated vision problems, diabetes or rheumatic problems and allergies.

More serious is the lagophthalmos, a disease that prevents the complete closure of the eyelids. It can be caused by temporary paralysis, birth defects or dall'ectropion, another disease characterized dall'eversione eyelid eyelid, resulting in fatigue and overexposure of the conjunctival surface. The treatment is the same for the two diseases and is a minor surgery to correct the position.

Diabetic retinopathy is directly related to diabetes. The diabetes have a higher concentration of blood sugar normal. This causes changes and thickening of blood vessels, especially capillaries, which prevents the normal functioning tissue oxygenation. Even the retina, rich in capillaries, is therefore subject to problems with diabetes. The eye disease symptoms are not immediately visible with the disease progresses you may experience thrombosis, vision loss, blurring, bleeding.