# General formula to design a freeform singlet free of spherical aberration and astigmatism: comment.

@article{ValenciaEstrada2020GeneralFT, title={General formula to design a freeform singlet free of spherical aberration and astigmatism: comment.}, author={Juan Camilo Valencia-Estrada and Jorge Garc'ia-M'arquez}, journal={Applied optics}, year={2020}, volume={59 11}, pages={ 3422-3424 } }

In their paper [Appl. Opt.58, 1010 (2019)APOPAI0003-693510.1364/AO.58.001010] González-Acuña et al. claimed: "an analytical closed-form formula for the design of freeform lenses free of spherical aberration and astigmatism." However, as we show here, their formula can only be applied when the object and image are both real, and the image is inversed; additionally, the refractive index in the object and image media is the same. Here, we present the complete solution of this particular formula.

## 5 Citations

### General formula to design a freeform singlet free of spherical aberration and astigmatism: reply.

- PhysicsApplied optics
- 2020

The comment made by Valencia-Estrada and García-Márquez to the paper consists of a trivial generalization of the formulation of APOPAI.

### Calculation of a lens system with one or two aspherical surfaces having corrected spherical aberration.

- PhysicsJournal of the Optical Society of America. A, Optics, image science, and vision
- 2020

The paper presents a detailed theoretical analysis of characteristics of a rotationally symmetric lens system with one or two aspherical surfaces having corrected spherical aberration and reduced…

### Analytic solution of the eikonal for a stigmatic singlet lens

- PhysicsPhysica Scripta
- 2020

We present the analytic solution of the eikonal equation for the stigmatic singlet lens. The solution is obtained by applying the homotopy that follows the Fermat principle of the stigmatic singlet…

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