Refractive errors can generally be divided into myopia, hyperopia and astigmatism.

Myopia:
Myopia is caused when the eyeball is too long or the lens is too thick, causing the image to be focused in front of the retina.

Farsightedness:
When the eyeball is too short or the lens is too thin, images are focused only behind the retina.

Astigmatism:
Is caused by a distorted or irregular cornea, usually inherited. May be present at birth and usually remain unchanged throughout life. Wearing appropriate glasses can enable patients to see clear images.

Eye sores:
The secretion of sebaceous glands in the eyelids is blocked, leading to bacterial growth and inflammation, which will form eye sores.

Pay attention to personal hygiene. You can use a cooked egg as a hot compress at home to accelerate the liquefaction of the sebum in the sore with heat, or have an ophthalmologist cut the sore open with a knife to release the sebum. Strabismus

Strabismus refers to the inability of the two eyes to focus on the same target at the same time, that is, one eye focuses on the target while the other deviates from it. Strabismus is a condition that requires careful management because:
A. It may be associated with abnormal brain development
B. It may lead to incomplete development of visual depth 
C. It may cause amblyopia 
D. It is unsightly and affects social interaction

Treatment options include wearing appropriate glasses, using eye drops, prisms, eye vision correction exercises, and strabismus correction surgery.

If due to eye disease or other reasons, the optic nerve system selectively receives signals from a single eye (left or right), it will cause amblyopia.

Causes:
Usually caused by refractive error, strabismus or other eye diseases (such as cataracts).

Treatment:
Cover the better eye to force the brain to receive signals from the weaker eye.

If the problem is not discovered until the child is past the age of visual development (e.g., eight to nine years old), amblyopia may not be correctable. The student may not be able to work in certain jobs that require high vision, such as aircraft piloting.