Abstract
Purpose: :
To test a novel Extended Depth Of Focus (EDOF) lens, potentially capability of correcting: Myopia, hyperopia with regular/ irregular astigmatism and presbyopia.Current methods of correcting these refractive errors are not optimal, not allowing simultaneous vision for far and near or correcting irregular astigmatism in spectacles and soft contact lenses.EDOF technology extends the depth of focus for a given lens or imaging system, without appreciable loss of energy. It is produced and incorporated as a coating or engraving on the surface any kind of- spectacles or contact lens
Methods: :
After optical bench testing for verification of simulation results, the technology was evaluated on small subject groups with spectacles and contact lenses on which the EDOF elements were incorporated. Five astigmatic (up to 2.00 D) and 10 presbyopic subjects (requiring 1.75-2D addition for near vision) were examined. The enhancing optical element was added to each of the subject's distance correction.
Results: :
The optical bench results showed correction of 2.00 D of astigmatism (including irregular astigmatism) and improvement of 2.5 D for the near distance. The evaluation over the trial group showed correction of 2.00 D for astigmatism and in presbyopic subjects the visual acuity for far and near distances was 6/6 and J1 respectively. The subjects' stereo perception, color vision and contrast sensitivity were not affected.
Conclusions: :
The EDOF system seems to provide a satisfactory single-lens solution for myopes and hyperopes with deficient accommodation ability and/or with irregular and regular astigmatism. Contact lens performance is apparently better than those of existing multi and bi-focal lenses.
Keywords: presbyopia • accomodation • astigmatism