The /æ/ vowel is spelled <a> followed by two consonants or by one consonant in a monosyllable. The /ɪə/ diphthong is spelled <ear>, <eer>, and <er> in the words hero and peri.
This contrast is between a short vowel and a diphthong with the sounds well separated in the mouth, so it should not cause any problems.
There is one pair involving a mildly taboo word: phallus/fearless.
Interesting pairs include:
The density value is low at 0.56%. The pairs make 22 semantic contrasts, giving a high loading of 91.7%.
as ears bad beard barrier beerier Barry beery cache kirsch Chad cheered Chas Cheers clad cleared dally dearly fad feared gad geared harrow hero harrows heroes has hears jazz jeers lad leered pad peered parry peri parries peris parry peri phallus fearless rally really sad seared shad sheared
John Higgins, Shaftesbury, November 2009