Hellers Tests is a term used to describe a series of clinical tests used to assess the vestibulo-ocular reflex. The word "Hellers" is pronounced as "hel-ers" /ˈhɛlərz/. The first syllable is stressed, and the vowel in the second syllable is reduced to a schwa sound. The word is spelled with a double L after the E because the letter E is unstressed and followed by a consonant. This spelling convention is common in English words like "compelling" and "controlled."