Abstract
Purpose: :
To produce a model eye with variable spherical aberration to estimate the effect of the aspheric surface on retinal images.
Methods: :
Using the model eye comprised of a camera lens and the CCD camera, an IOL was put in a water cell, and the retinal images of the aspheric IOLs (FY60AD [Hoya] and SN60WF [Alcon]) and spherical IOLs (YA 60BBR [Hoya] and SN60AT [Alcon]) with a 5-mm aperture were captured with the CCD camera. The image contrast of the optotypes at 0.5, and 1, 2, 3, 4, and 5 meters were compared. To add corneal spherical aberration to the model eye, a phase plate of spherical aberration was put between the camera lens with no spherical aberration. Three phase plates with spherical aberrations of 0.16, 0.2, and 0.27 micrometer (6-mm diameter) were tested to determine the effect of the spherical aberration. The green filter for color separation was used to remove the affect of chromatic aberration. The FY60AD and SN60WF were designed to compensate for 0.16 and 0.2 micrometer of corneal spherical aberration respectively.
Results: :
The images of the two aspheric IOLs had high contrast when compensating for 0.16 micrometer of spherical aberration. With more than 0.27 micrometer of synthetic spherical aberration, the contrast of the retinal images of the spherical IOLs decreased; however, the depth of field was wider.
Conclusions: :
The effect of aspherical IOLs to compensate for corneal spherical aberration could be visualized and evaluated objectively using the new eye model camera.
Keywords: intraocular lens • aberrations • optical properties