Physetocaris microphthalma was previously placed in its own family (Physetocarididae) and superfamily (Physetocaridoidea).

[1] Molecular phylogenetic analysis has revealed that the species actually belongs within the family (Pandalidae) and superfamily (Pandaloidea).

[2] The genus and species were described in 1940 by Fenner A. Chace Jr.

Adults have no eyes, and are missing the last segment of the first pereiopod, which is therefore unable to form a claw.

[3] P. microphthalma is rare, with only 35 specimens counted in a 1985 review.