I am getting bad eye sight. Which kind of eye doctor to see?

An Ophthalmologist. You should see an ophthalmologist. There are many possible reasons for poor vision. Some reasons are very dangerous such as bleeding from diabetic retinopathy or retinal detachment. Others such as glaucoma may be less noticeable by the patient. Infections, cancers and vascular changes of hypertension or ischemia are other dangerous problems that are discovered and treated only by a trained md.