You should ideally visit an ophthalmologist once a year to get your eyes checked. Apart from this, you should see an ophthalmologist when you have:
1. Decreased/blurred vision
2. High blood pressure
3. Diabetes mellitus
4. AIDS
5. Thyroid problems
6. Excess tearing
7. Eyelid abnormalities
8. Double vision
9. Loss of peripheral vision
10. Redness or itching of eyes
11. Abnormal eye discharge

An ophthalmologist is trained at both performing tests to check if you have any eye issues as well as at performing surgeries.

To become an opthalmologist, you first need to get an MBBS degree (5.5. yrs course) after which you need to pursue specialisation in opthalmology via an MD or DNB for 3 years.

Yes. An opthalmologist can check your eyes if you have any vision-related issues and suggest you to get contact lenses to wear.

There are several specialties in opthamology such as cataract surgery, neuro opthalmology, retina specialst, pediatric opthalmology among others.