Opeadoscope or Opeidoscope: How To spell?

The word Opeadoscope is misspelled against Opeidoscope, a noun meaning "An instrument, consisting of a tube having one end open and the other end covered with a thin flexible membrance to the center of which is attached a small mirror. It is used for exhibiting upon a screen, by means of rays reflected from the mirror, the vibratory motions caused by sounds produced at the open end of the tube, as by speaking or singing into it."

Word contains consecutive vowels 'EI' in between alphabets op & doscope is misspelled as 'EA'
Wrong Spelling:  op-ea-doscope 
Correct Spelling:  op-ei-doscope 
Find more incorrect spellings of Opeidoscope to spell right way.