To the Editor.
—The careful reader of our article,1 which appeared in the September Archives, will have noticed that equation 5 is incorrect as printed. At neutralization, ie, when the instrument image (I3) equals the emergent image (I3), the relative speed of the reflex (RSR) is not equal to one, as it should be according to the article. The formula is corrected by changing the plus sign to a minus sign.
Boeder P, Kolder HE. A Formula Correction. Arch Ophthalmol. 1985;103(4):477. doi:10.1001/archopht.1985.01050040019005