Rayner EMV and Eyhance set for near

I don't have either of these lenses, but I have looked at the technology they claim to use. My thoughts:

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Eyhance - This lens changes the power based on the radius of the lens with most of the power change concentrated at the middle of the lens. This makes the effective lens power change as the pupil constricts down in brighter light. This in effect stretches the point of focus of the lens which gives it more depth of focus with a small cost in visual acuity. J&J compares it to the Tecnis 1 monofocal which has the least depth of focus of all monofocal lens, so the Eyhance looks better in comparison. The increase in depth of focus is quite minor, and compared to the Clareon potentially insignificant, and compared to the enVista it may even have less depth of focus. If used in the near eye of a mini-monofocal configuration it potentially could be targeted at -1.25 D instead of the more standard -1.50 D. Another more conservative approach which I think would be better is to still target it at -1.50 D, and take any extra depth of focus one may get as a bonus.

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Rayner EMV - This lens is much harder to pin down as to what it really does. The EMV stands for enhanced monofocal vision, and it is said to be specially designed for that purpose. The problem is a lack of published data like a defocus curve that justifies this claim. One feature that does have some limited backup with data is the claim that the defocus curve has a boost to the left of the peak visual acuity point. This seems to be unique to this lens. In the distance eye this has little value as it is in the distance zone as being beyond infinity. If the lens is targeted a little myopic it may very slightly reduce the loss in visual acuity at distance, but the effect is likely to be insignificant. And in the near eye it may improve visual acuity in the intermediate distance range and be more significant. However, I find that with properly targeted standard monofocal lenses there is no real issue with the intermediate range that needs improvement. So I think the bottom line is that there may be some very minor probably more theoretical than actual benefits to the EMV in a monovision configuration.

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I think overall the key to success with mini-monovision is sticking to the process with careful targeting rather than becoming distracted with technology. Key points in my opinion are:

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1. Target -0.25 D in the distance eye and do it first
2. Wait 5 weeks to get a stable final refraction so you know where you land.
3. If the outcome is -0.25 D then it makes sense to target 1.5 D more in the near eye, or -1.75 D to give the optimum near vision.
4. The amount of near eye myopia can be tested using the distance eye corrected to different levels of myopia using OTC reading glasses to confirm.
5. If -1.75 D is confirmed, then target the near eye to that. Outcome from the first eye should make the targeting in the second eye more accurate.

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   Hope that helps some,