Abstract
Purpose: :
To compare through focus subjective quality of vision and objective image quality metrics in three multifocal contact lenses wearers.
Methods: :
Through focus subjective assessment of the quality of vision was measured each 0,1 diopters (from -4 to +3 D) under cyclopentolate 0,5% and through a 5mm artificial pupil diameter) with the use of 5 items grading scale according to ITU-R 500 recommendations in 5 conditions (naked eye, Air Optix Multifocal High® wearer, Air Optix Multifocal Low® wearer, Proclear Multifocal Distance Addition 1D wearer and Proclear Multifocal Distance Addition 2,5D wearer). The target was three high-contrast letters of 0.4 logMar size. The subject astigmatism was compensated using an optic adaptative system (CRX1®, Imagine Eye). Eighteen through focus OTF and MTF-based image quality metrics were calculated using the wavefront of the eye wearing the contact lens.
Results: :
The best correlation (r2=0,81) between objective measurements and subjective assessment was obtained with visual Sthrel Ratio based on MTF measurements between 3 and 12 cycles/degrees (VSrMTF3-12). However, none of the eighteen objective image quality metrics was able to predict the bimodal subjective curve obtained with Proclear Multifocal Distance Addition 2,5D contact lens.
Conclusions: :
The VSrMTF3-12 image quality metrics may be used to predict subjective quality of vision for naked eye and in low-addition multifocal contact lenses wearers. Nevertheless, the bimodality of some subjective curves could not be estimated with these objective quality of vision items.
Keywords: visual acuity • adaptation: blur • depth