The /ɔɪ/ diphthong is spelled <oi> and <oy>. The /ɪə/ diphthong is spelled <eer>, <ear> or <ie>.
This is a contrast between two diphthongs with different starting positions and different directions of movement. It is not a problem for learners.
The density figure is 3.45%. The set makes 18 semantic contrasts giving a loading of 62.1%.
boy beer boys beers boy bier boys biers buoy beer buoys beers buoy bier buoys biers buoyed beard cloy clear cloyed cleared cloys clears doily dearly joy jeer joyed jeered joys jeers loin lien loins liens noise nears poise peers poise piers Roy rhea toy tear toys tears toy tier toys tiers void veered
Credit: John Higgins