In this comment we discuss recent results presented by P. Afanasiev on the optical properties of microcrystalline BaMoO 4 and BaWO 4 [Materials Letters 61 (2007) 4622]. Its aim is to show that the band-gap energy reported in that work for BaWO 4 is not reliable and largely underestimate the correct value. As a consequence of it, the challenge made in Ref. [P. Afanasiev, Materials Letters 61 (2007) 4622] to the previous understanding of the electronic structure of scheelite-type compounds is not valid.