Problem in Eye For Astigmatism. Normal?

Doctor, I'm 14 Years Old. I Have Sufferings From Myopic Astigmatism For 1.5 Years. Due To This, I'm Having Blurry Vision And Double Vision. I Went An Opthalmologist Who Prescribed Me Glasses For Astigmatism And Checked Me With Slit-Lamp. His Given Glasses Reduced My Blurry Vision And Double Vision, But His Prescribed Glasses Was Failed To Remove My Double Vision Completly. But, His Given Glasses Was Able To Give 6/6 To Me. From Doubts And Fair About Some Diseases, Yesterday I Went To A Different Opthalmologist And He Also Checked My Eye Using Slit-Lamp. Then He Prescribed Me Glasses. His Prescribed Glasses Reduced My Double Vision At 80-90% But Not Fully. Then, I Informed The Doctor That The Double Vision isn't Going Even After Wearing Glass. Then The Second Doctor Told Me That The Remnant Double Vision (Which I'm Having Even After Wearing Glass) is Normal And It Will Stay Even After Wearing Glasses. Why The Doctor Say That The Remnant Double Vision is Normal? Pls Answer, Doc.