The Effect of Cycloplegia on the Determination of Refractive Error by the Ophthalmetron®

The Ophthalmetron® was used to measure the refractive error of 10 male optometry students. Although there was a high incidence of invalid readings, more repeatable results were obtained with use of a cycloplegic. Measurements made under cycloplegia revealed 0.41 D more hyperopia but no differences in astigmatism as compared to the noncycloplegic refraction. Instrument myopia was shown not to be a factor.