Ideal Target Refraction for Monovision

Based on the search results, there is some variation in the recommended target for the near eye in monovision, but most sources suggest a range between -1.00 D to -2.00 D of myopia. Here are the key points:

## Recommended Targets

– Dr. Ehud Assia recommends targeting between -1.5 D and -2.0 D for the near eye, with -1.75 D being optimal in his experience[1].

– One source suggests a target refraction of -1.25 D sphere for the near eye, noting this is more effective for pseudophakia compared to phakia[3].

– Another practice targets -1.50 to -2.50 D of myopia in the nondominant eye for pseudophakic monovision[5].

– For customized monovision using multifocal IOLs, one practice aims for slight myopia of -1.00 D in the nondominant eye[5].  But with modern multifocal IOLs the best target is plano as the implant is designed to work at distance, intermediate and near.

## Factors Affecting Target Selection

– The ideal target may depend on factors like pupil size, patient age, ideal reading distance, hobbies, occupation (computer vs needlepoint), height (tall patients have longer arms and can tolerate holding reading materials further out) and visual needs[5].

– Mini-monovision approaches may use a lower target, around -0.75 D, especially when combined with extended depth of focus lenses[2].

– Some surgeons prefer to determine the target for the second eye after assessing the results of the first eye surgery[1].

## Considerations

– Lower levels of myopia (e.g. -1.25 D) may help preserve stereoacuity and avoid reduced contrast sensitivity associated with higher levels of anisometropia[3].

– The target should balance providing good near vision while minimizing side effects and maintaining binocular vision[1][3].

– Patient satisfaction tends to be high with monovision targets in the -1.00 to -1.50 D range[3].

In summary, while there is no single universally agreed-upon target, most sources recommend aiming for -1.25 D to -1.75 D of myopia in the near eye for monovision, with some flexibility based on individual patient factors and preferences.

Citations:
[1] https://www.eyeworld.org/2019/choosing-between-monovision-and-multifocals/
[2] https://www.presbyopiaphysician.com/issues/2022/june/modernizing-monovision/
[3] https://crstodayeurope.com/articles/2009-oct/1009_12-php/
[4] https://www.reviewofophthalmology.com/article/which-lens-for-which-patient
[5] https://crstodayeurope.com/articles/2011-mar/monovision-strategies/
[6] https://www.aao.org/education/current-insight/minimonovision-reducing-spectacle-dependence-after
[7] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7035885/
[8] https://patient.info/forums/discuss/monovision-first-eye-for-near-vision-804519