Sagittal height differences of disposable soft contact lenses.

Purpose: We aim to improve contact lens fitting by using an innovative and simple photogrammetry imaging system to find the sagittal height (SAG) of soft contact lenses.

Methods: Eleven different types of commercially available soft contact lenses were measured, and five different lenses per package of each lens type were evaluated. The lenses were inserted in a polymethyl methacrylate cell with parallel faces containing a solution of saline and fluorescein to improve the contrast against the background.

Lens internal curvature effects on age-related eye model and lens paradox.

The gradient index (GRIN) model is the most accurate way to represent the eye lens which, because of its growth mode, is a lamellar, shell-like structure. The GRIN is thought to provide optical properties that counteract age-related changes in curvature that would otherwise create an increasingly myopic eye: the so-called lens paradox. This article investigates how fine-tuning the refractive index and the internal curvatures of the lenticular indicial contours may prevent the ageing eye from becoming myopic.

Fractal Features and Surface Micromorphology of Unworn Surfaces of Rigid Gas Permeable Contact Lenses.

Purpose: The aim of this exploratory study was to investigate the micromorphology of surfaces of rigid gas permeable (RGP) contact lenses (CLs) using atomic force microscopy (AFM) followed by fractal analysis.

Materials And Methods: In order to characterize in a quantitative manner the micromorphology of surfaces of new and unworn RGP CLs made of twelve different materials, AFM was taken and then analyzed using fractal methods. Surface topography was sampled in an intermittent-contact mode in air, on square areas of 5 × 5 µm (MultiMode with Nanoscope V (Bruker).

Morphological Properties of Siloxane-Hydrogel Contact Lens Surfaces.

Purpose: The aim of this study was to quantitatively characterize the micromorphology of contact lens (CL) surfaces using atomic force microscopy (AFM) and multifractal analysis.

Materials And Methods: AFM and multifractal analysis were used to characterize the topography of new and worn siloxane-hydrogel CLs made of Filcon V (I FDA group). CL surface roughness was studied by AFM in intermittent-contact mode, in air, on square areas of 25 and 100 μm, by using a Nanoscope V MultiMode (Bruker).

[Representation and mathematical analysis of human corneal surface].

In the description and analysis of human corneal surface are used various mathematical models based on parametric representations, used in biomechanical studies and 3D solid modeling of the cornea. Mathematical models are important into the biomechanics of the cornea to model the corneal behavior. Corneal biomechanics also has the potential to improve outcomes in refractive surgery.

[Representation and mathematical analysis of human crystalline lens].

The surface of human crystalline lens can be described and analyzed using mathematical models based on parametric representations, used in biomechanical studies and 3D solid modeling of the lens. The mathematical models used in lens biomechanics allow the study and the behavior of crystalline lens on variables and complex dynamic loads. Also, the lens biomechanics has the potential to improve the results in the development of intraocular lenses and cataract surgery.