Omatidia or Ommatidia: How To spell?
The word Omatidia is misspelled against Ommatidia, which is plural of "Ommatidium"
Ommatidia has double "mm" is mispronounced as "m"Remember double 'MM' in between the strings o & atidia which should not be misspelled with single 'M'
Wrong Spelling:  o-m-atidia  Correct Spelling:  o-mm-atidia 
Find more wrongly spelled words of Ommatidia to spell it well.