Citation: Alionte, C.G.; Ungureanu,
L.M.; Alexandru, T.M. Innovation
Process for Optical Face Scanner
Used to Customize 3D Printed
Spectacles. Materials 2022, 15, 3496.
https://doi.org/10.3390/ma15103496
Academic Editors: Ludwig Cardon
and Clemens Holzer
Received: 31 March 2022
Accepted: 8 May 2022
Published: 13 May 2022
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Article
Innovation Process for Optical Face Scanner Used to Customize
3D Printed Spectacles
Cristian Gabriel Alionte
1
, Liviu Marian Ungureanu
2,
* and Tudor Mihai Alexandru
1
1
Mechatronics and Precision Mechanics Department, Faculty of Mechanical Engineering and Mechatronics,
University Politehnica of Bucharest, 060042 Bucharest, Romania; cristian.alionte@upb.ro (C.G.A.);
tudor.mihai2098@yahoo.ro (T.M.A.)
2
Mechanisms and Robots Theory Department, Faculty of Industrial Engineering and Robotics,
University Politehnica of Bucharest, 060042 Bucharest, Romania
* Correspondence: ungureanu.liviu.marian@gmail.com; Tel.: +40-726-329-247
Abstract:
Many people for different reasons end up wearing glasses to correct their vision. From time
immemorial, there has been an unquestionable ability to associate people with glasses. Designing
the glasses according to the physiognomy of each person opens a new path for a completely new
optical experience. The frames are designed to fit perfectly on the face, are comfortable on the nose,
and are positioned at an optimal distance from the cheeks and eyelashes. Three-dimensional printing
technology offers the possibility to customize any form of glasses at a low cost with average quality.
In this type of technology, the printer receives a digitized model of the spectacle frame (usually in
STL file format) that must meet the parameters related to the wearer’s anatomy. Therefore, this paper
presents an innovative process, an optical method used to scan the wearer’s face to design a parame-
terized design of the spectacle frames. The procedure has a measurement phase for quantifying the
anatomical features of the wearer’s face, a para-metric design phase of the glasses for adjusting the
design parameters according to the anatomical characteristics, and a manufacturing phase in which
the custom eyeglass frame will be manufactured using 3D printing technology. The aim of this study
was to create an innovative process that could be tested as an educational 3D printing system that
could be used by undergraduate students (studying under an optometry program), a process that
would begin at optometric prescription stage and can be used in the educational laboratory of the
Department of Mechatronics and Precision Mechanics from the Politehnica University of Bucharest.
Using this method we obtained a custom spectacle frame that can be prototyped using 3D printing.
The 3D-printed polylactic acid (PLA) frames are lightweight, flexible, durable, and the innovative
photogrammetry process gives designers the ability to create custom designs that cannot be created
with traditional manufacturing techniques.
Keywords: 3D printing; optical scanning measurement; 3D spectacle frames
1. Introduction
Spectacle frames are easy to manufacture using 3D printing methods because this
technology permits their manufacturing in many designs, sizes, and shapes [
1
]. The shape
parameters are linked with the anatomical features of the wearer for optimal positioning
of the lenses in front of the eyes to align the center of the lens with the optical eye axis
and to achieve improved monocular and binocular vision according to the prescription
of the optometrist. Therefore, the spectacle design must respect certain dimensions, be
comfortable around the temples and on the nose, must be aesthetic, and must fit the
parameters of the anatomical features that allow the spectacles to be worn effortlessly. Each
person has a different facial anatomy and the 3D printing of spectacle frames seems to be
a good solution that solves this problem through easy customization without having to
make compromises [
2
]. The concept, design, and prototyping are not only accurate, but also
Materials 2022, 15 , 3496. https://doi.org/10.3390/ma15103496 https://www.mdpi.com/journal/materials
