We read your informative article on corneal total astigmatism measurement in the September 2014 issue (Sanfilippo et al. 2014). In ‘Methods’ although the intention of making a comparison between different age groups is very interesting, different types of drugs were used and this could lead to incorrect conclusions. The purpose of the article was to investigate the appropriate age cut-off for cycloplegia in refraction, but the comparison should have been made with drugs that offer the same cycloplegic potential. Several studies have shown that cyclopentolate has more cycloplegic effect than tropicamide and it reduces the accommodative amplitude in adults (Mutti et al. 1994; Owens et al. 1998; Hofmeister et al. 2005). The authors concluded that cycloplegia is not required to provide an estimation of refractive error for adults; we believe that one cannot come to this conclusion being as tropicamide was used in the adult group. As discussed above, this is a drug that produces less cycloplegia than cyclopentolate. Therefore, the amplitude of accommodation will not remove efficiently and autorefraction may show erroneous data given the remaining reserve accommodation. Although some authors consider that this is not necessary, based on the concept that the amplitude of accommodation is lost with age, the findings in their studies have shown no significant differences between perform it. It is also well known based on many studies that cycloplegic refraction is very important in adults. Many authors conclude that the lack of cyclopegia can show an overestimation of myopia or an underestimation of hyperopia or emmetropia. This can lead to a wrong spherical equivalent, even in patients between the ages of 20 and 50. Therefore, cycloplegia should be considered the gold standard for epidemiological studies of refraction in both children and adults (Morgan et al. 2015). In other studies, sensitivity and specificity of non-cycloplegic autorefraction were determined using cyclopentolate and tropicamide. They found that the absence of cyclopegia leads to significant errors in the measurement of refraction which ceases to be important in adults over the age of 50 (Fotouhi et al. 2012).