My son has thalassemia minor and has eye problems where he needs to wear thick glasses. he has recently been complaining of severe ha's, and is dizzy?

See the doctor: He should check with his doctor to see if his vision has changed and he needs new glasses, to make sure he is not anemic, to see if he might have a viral illness causing these symptoms.

Change in eyeglasses: This sounds with the limited info that he may need a change in eyeglasses that could be causing eyestrain and headaches. You should see an ophthalmologist to determine that nothing else is happening.