Quality of vision with traditional monovision versus modified monovision

Abstract

Purpose To compare binocular subjective quality of vision with modified monovision (MMV) (ie different combinations of spherical (SA4) and secondary spherical (SA6) aberration on each eye) versus traditional monovision (TMV) with different level of anisometropia Methods A numerical eye model was used to generate images (ie three 0.4 logMAR high contrast letters) viewed through a 4.7mm pupil, degraded by various condition of SA and for proximities from ‐5D to 5D (Naked eye, SA4‐0.4μm, SA4+0.4μm, SA4‐0.4 and SA6+0.2μm, SA4+0.4 and SA6‐0.2μm). Binocular vision was simulated using a 3D‐NVIDIA video device projecting different image on each eye. Binocular through‐focus (TF) quality of vision was evaluated using a grading scale (ITU‐R 500 recommendation) by four subjects with TMV for different level of anisometropia (ie 0.5 to 3D at 0.5D step) and with various combination of MMV Results Area under TF curve (ie a way to evaluate quality of vision) measured for a fair or higher image quality was increased with TMV and MMV compared to naked eye because of the summation of the two best monocular curves. With TMV, a 2.5D anisometropia was the more effective to increase area under TF curve with however a lack of intermediate vision. With MMV the greatest increase of quality of vision was obtained with reverse profile of SA4 and SA6 on each eye (ie SA4‐0.4 and SA6+0.2μm on one eye and SA4+0.4 and SA6‐0.2μm on the other eye). Compared to TMV, reverse profiles of MMV showed a significant benefit in improving area under TF curve thanks to a better quality of intermediate vision Conclusion MMV especially with reverse profiles of SA improved overall quality of vision without the lack of intermediate quality of vision intermediate quality of vision induced by TMV

Correction of presbyopia: old problems with old (and new) solutions

“…Although different distances can be focused by employing different optical powers in each eye (for example, chameleons 16 ), evolution has not developed this approach for humans for whom anisometropia is rare and a possible cause of visual cortical disruption if present in early life (amblyopia, loss of stereopsis). 22 However, inducing anisometropia in older presbyopic or pseudophakic patients ('monovision') has been shown to expand the binocular depth of field by generating clear bifocality of the binocular visual system, [23][24][25][26] and high-quality vision at two distances (Figure 1). 27 The success of monovision hinges on the observation that vision with one focused and one defocused eye is dominated by the focused image, 28 as shown quantitatively in studies of contrast sensitivity [23][24][25] and visual acuity.…”

“…22 However, inducing anisometropia in older presbyopic or pseudophakic patients ('monovision') has been shown to expand the binocular depth of field by generating clear bifocality of the binocular visual system, [23][24][25][26] and high-quality vision at two distances (Figure 1). 27 The success of monovision hinges on the observation that vision with one focused and one defocused eye is dominated by the focused image, 28 as shown quantitatively in studies of contrast sensitivity [23][24][25] and visual acuity. 26,29 The improvement in near vision created by correcting one eye can be dramatic, but monovision does not replicate the range of high-quality vision observed in young adults (Figure 1).…”