The design for the Multicenter Trial of Cryotherapy for Retinopathy of Prematurity revolved around our desire to test whether cryotherapy would prevent blindness. With that concept in mind, we used a binary functional outcome of favorable vs unfavorable visual acuity. Visual acuity of 20/200 or worse is customarily classified as legal blindness. This was our unfavorable visual acuity outcome definition, which produced the semantic oddity of the term favorable to describe the opposite category, even though this would include eyes that were somewhat visually impaired. Thus, Jalali and Hussain correctly note that visual acuity in the range of 20/60 to 20/200 is not necessarily favorable in the usual sense of the word.
Palmer EA. We Can Aim at Better Results in Coming Years—Reply. Arch Ophthalmol. 2006;124(4):605-606. doi:10.1001/archopht.124.4.605