Non-contact lensless holographic reconstruction of diffractive intraocular lenses profiles.

A lensless compact arrangement based on digital in-line holography under Gabor's regime is proposed as a novel contactless method to assess the profile of multifocal intraocular lenses (MIOLs) which are conformed by several diffractive rings. Diffractive MIOLs are a widely adopted ophthalmologic option for the correction of presbyopia in patients undergoing cataract surgery. The MIOL optical design might introduce non-negligible optical performance differences between lenses as well as the introduction of undesirable photic phenomena (such as halos and glare) affecting the vision of users.

Soft Contact Lens Engraving Characterization by Wavefront Holoscopy.

Permanent engravings on contact lenses provide information about the manufacturing process and lens positioning when they are placed on the eye. The inspection of their morphological characteristics is important, since they can affect the user's comfort and deposit adhesion. Therefore, an inverted wavefront holoscope (a lensless microscope based on Gabor's principle of in-line digital holography) is explored for the characterization of the permanent marks of soft contact lenses.

Vecto-keratometry: determination of anterior corneal astigmatism in manual keratometers using power vectors.

Background: A new keratometric routine that employs power vector management for manual keratometers is described. This study evaluates the agreement of the new proposed keratometric technique with the classical one.

Research Design And Methods: The applicability of a new keratometric routine was verified using Helmholtz's and Javal's keratometers.