The influence of rotational error and axial shift of toric intraocular lenses on residual astigmatism.

Purpose: Accurate alignment of Toric Intraocular Lens (T-IOLs) in cataract surgery is crucial for good visual outcomes. The purpose of this study was to evaluate the influence of rotation, axial shift and their combined effects on the refractive error and image quality of a wide range of T-IOL powers (from +1.50 D to +6.

Subjective Straylight Index: A Visual Test for Retinal Contrast Assessment as a Function of Veiling Glare.

Spatial aspects of visual performance are usually evaluated through visual acuity charts and contrast sensitivity (CS) tests. CS tests are generated by vanishing the contrast level of the visual charts. However, the quality of retinal images can be affected by both ocular aberrations and scattering effects and none of those factors are incorporated as parameters in visual tests in clinical practice.

Corneal retardation time as an ocular hypertension disease indicator.

A detailed analysis of the corneal retardation timeas a highly related parameter to the intraocular pressure (IOP), and its plausible role as an indicator of ocular hypertension disease.A simple theoretical expression foris derived within the corneal viscoelastic model of Kelvin-Voigt with 3 elements. This retardation time can be easily calculated from the well-known signal and pressure amplitudes of non-contact tonometers like the Ocular Response Analyzer (ORA).

Peripheral refraction under different levels of illuminance.

Peripheral refraction is believed to be involved in the development of myopia. The aim of this study was to compare the relative peripheral refraction (RPR) at four different levels of illuminance, ranging from photopic conditions to complete darkness, using an open-field autorefraction method. The RPR was calculated for each eccentricity by subtracting central from peripheral autorefraction measurements.