What are the common eye diseases?

Ocular diseases can generally be categorized into the following groups according to their causes, sites of onset, and clinical manifestations:

1. Refractive errors: Including myopia (nearsightedness), hyperopia (farsightedness), astigmatism, and presbyopia, these mainly affect visual clarity.

2. Conjunctivitis: Inflammation of the conjunctiva caused by bacterial, viral, or allergen irritation. Common symptoms include red eyes and increased eye discharge.

3. Corneal diseases: Such as corneal ulcers and keratitis, these are caused by infections, injuries, or metabolic abnormalities and can lead to vision loss or even blindness in severe cases.

4. Glaucoma: Damage to the optic nerve caused by elevated intraocular pressure. It typically presents no obvious symptoms in early stages but can lead to blindness in advanced stages and causes irreversible vision impairment.

5. Cataracts: Clouding of the lens that affects the entry of light into the eye, resulting in blurred vision. These commonly occur in elderly individuals and can be effectively treated with surgery.

6. Macular degeneration: Degeneration of the macula leading to impaired central vision. Common in middle-aged and elderly individuals, it is one of the primary causes of blindness in the elderly.

7. Fundus diseases: Such as retinal diseases, optic nerve disorders, and visual pathway diseases, these affect the visual signal transmission pathway.

8. Orbital diseases and ocular trauma: Involving pathological changes in orbital tissues and external injuries to the eye.