A person who has eye symptoms should be checked by a doctor. However, some eye diseases cause few or no symptoms in their early stages, so the eyes should be checked regularly (every 1 to 2 years or more frequently if there is an eye condition) by an ophthalmologist or an optometrist. An ophthalmologist is a medical doctor who specializes in the evaluation and treatment (surgical and nonsurgical) of eye disorders. An optometrist is a health care practitioner who specialize in the diagnosis and treatment of vision or refractive problems (refractive errors).
Diagnosis of eye disorders is initially based on the person's symptoms, the appearance of the eyes, and the results of an examination.
To view the structures inside the eye, see see Figure: An Inside Look at the Eye.