Omatidium or Ommatidium: How To spell?
The word Omatidium is misspelled against Ommatidium, a noun meaning "One of the single eyes forming the compound eyes of crustaceans, insects, and other invertebrates."
Ommatidium has double "mm" is mispronounced as "m"Remember double 'MM' in between the strings o & atidium which should not be misspelled with single 'M'
Wrong Spelling:  o-m-atidium  Correct Spelling:  o-mm-atidium 
Check more misspelled words of Ommatidium to spell it correct.