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1

Measurement of oxygen permeability of contact lenses based on analysis of porosity

Lewandowska M., Jasińska-Kwaśnik W., Jóźwik A., Siedlecki D.

Interdisciplinary Journal of Engineering Sciences

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2015

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Vol. 3, no. 1

1--5

EN

Oxygen permeability seems to be the most important parameter characterize the contact lens. Lenses, which permeable more oxygen to the cornea are safer, reduce the risk of infection and provide greater comfort of wearing. Oxygen permeability of contact lenses might be calculated by analysis of porosity of its surface. With using special program the size and number of pores on definite area was calculated and dependence of permeability and hydration on porosity were established.

2

Retinal images in optomechanical eye model with monofocal intraocular lens

Józwik A., Nowak J., Siedlecki D., Zajac M., Zarówny J.

Optica Applicata

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2011

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Vol. 41, nr 3

593--605

EN

Intraocular lens (IOL) is an artificial lens implanted into the eye. It usually replaces the existing crystalline lens, which is clouded over due to a cataract. In order to evaluate the optical performance of different IOLs an optomechanical model of human eye was developed. This model closely reproduces anatomical and optical properties of the average human eye. This makes it possible to measure the optical performance of different types of intraocular lenses and to estimate the influence of their location in eye on quality of vision. Four monofocal intraocular lenses were taken for analysis. The analysis of the quality of retinal images was carried out by means of either qualitative image comparison or physical quantities estimation. The analysis of LSF and MTF shows that the performance of the lenses tested changes slightly with differences in their design and/or material.

3

New shape of a videokeratometric illuminator

Siedlecki D., Kasprzak H.

Optica Applicata

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2002

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Vol. 32, nr 4

665-672

EN

The aim of this paper is to define such shape of a videokeratometric Placido disc-based illuminator that would guarantee flat image formation and, consequently, sharp and reliable information an corneal geometry. It is especially important for contact lens fitting to have reliable corneal data in a corneal peripheral area. It has been proved that shape of this stimulator profile depends on assumed corneal geometry. The ellipsoidal corneal shape has been assumed. The results show that the surface on which Placido rings are painted should have a cigar-like shape. Probably none of the devices used currently in clinical practice have such shape.