The need for affordable and sustainable ophthalmic systems for measurement and
correction of refraction is well recognized. Power-adjustable spectacles based on the …

Power-adjustable spectacle lenses, based on the Alvarez–Lohmann principle, can be used
to provide affordable spectacles for subjective refractive errors measurement and its …

Purpose To establish the optical performance of currently available Alvarez variable‐power
spectacles in relation to their possible utility for ametropes and presbyopes. Methods Two …

We present a comprehensive approach for the design of adjustable-focus lenses based on
the Alvarez principle. The design methodology consists of dividing the lens into two parts …

We first explore the operating principle and optical performances of dioptric-power and
astigmatism-variation lens doublets based on the LW Alvarez design. These fall within the …

Abstract colon; A new variable power cross-cylinder lens set is described. It differs from the
well known Stokes variable power cross-cylinder lens set, which is made of cylinder lenses …

The assembly effort of optical systems can be reduced immensely by the use of appropriate
manufacturing technologies. For refractive optical systems with a common axis of symmetry …

The theory of third-order aberrations for a system of rotationally symmetric aspheric thin
lenses and relations for calculation of the shape of rotationally symmetric aspheric spectacle …

We present and characterize an optical zoom system with lateral movement of an Alvarez
freeform lens for imaging. Mathematical analysis for determining the required freeform …

Purpose. We describe how to construct a low-cost and robust variable astigmatism-
correcting device manufactured using a pair of identical commercial ophthalmic lenses …