Comment on 'Color astrophotography with a 100 mm-diameter f/2 polymer flat lens', Appl. Phys. Lett. 126, 051701 (2025)

It is argued that the lens described in the paper commented upon has a focussing efficiency of less than 0.03% and an angular resolution for broadband radiation that is an order of magnitude worse that the diffraction limit. Furthermore incident radiation that is not focussed will lead to background fog in the image plane.