• astigmatism

In a recent perspective by Morlet et al¹ there are a number of omissions and fundamental errors of content that lead to erroneous conclusions. These significant inaccuracies overlooked in the review process compromise the article's broad contribution.

In Morlet et al's attempt to detail “the use and limitations of vectors . . . for the analysis of change in astigmatism” (p 1127) they display an incomplete understanding of the subject. They have made a valiant attempt to assemble an abundance of historical and contemporary references on a subject of significant interest, but key material has been omitted or misquoted. This has resulted in leading statements in the article, in both the body of the text and even the conclusion, that require re-evaluation and substantial revision.

The most obvious omission is the paper's absence of any discussion of the difference vector, a precise absolute measure of surgical error described in reference 70.² When the difference vector is related to the treatment (that is, TIA or target induced astigmatism vector) one has an extremely useful relative value of success of astigmatism treatment. Morlet et al have overlooked this key vectorial entity and struggle to find any …