The /ɔɪ/ diphthong is spelled <oi> and <oy>. The /eə/ diphthong is spelled <are>, <ear> or <air>.
This is a contrast between two diphthongs with different starting positions, different directions of movement and different lip-rounding. It is not a problem for learners.
The density figure is 2.3%. The set makes 10 semantic contrasts giving a loading of 56%.
boy bare boys bares boy bear boys bears buoy bare buoyed bared buoys bares buoy bear bouy bears coign cairn coigns cairns coin cairn coins cairns Lloyd's lairds poise pairs poise pears toy tare toys tares
John Higgins, Shaftesbury, December 2009