The Rayner EMV Lens: A Wider Range of Vision, Without the Haloes

Most patients coming to discuss cataract surgery arrive with the same two hopes and the same one fear. They hope to see clearly in the distance, and they hope to be less dependent on glasses. They fear the halo and starburst stories they have heard about premium lenses. For a large proportion of the patients Mr Neil Modi sees in Surrey, the Rayner RayOne EMV sits precisely in that gap.

What follows is how Mr Modi explains the lens in his own consulting room, including the parts of it that do not appear in the manufacturer's brochure.

What the RayOne EMV lens is

The RayOne EMV is what the field calls an enhanced monofocal, or monofocal-plus, intraocular lens. It is manufactured by Rayner in Worthing — the only company making intraocular lenses in the UK, and the company that made Sir Harold Ridley's first lens in 1949. The EMV optic was developed in collaboration with Professor Graham Barrett, and uses controlled positive spherical aberration rather than a diffractive surface to extend the range of vision.

That distinction matters more than the marketing language around it, so it is worth unpacking.

How it works, and why the mechanism matters

A standard monofocal lens has one focal point. Set it for distance, as we almost always do, and driving and television are sharp while everything closer requires glasses. It is a reliable, high-quality solution, and it remains the correct answer for many eyes.

A multifocal or trifocal lens takes a different route. It splits incoming light between two or more focal points using concentric diffractive rings. The patient gains reading vision, but light that is split is light that is shared, and some patients perceive that as haloes around headlights, glare at night, or a modest drop in contrast.

The EMV does not split light. It is a truly non-diffractive optic, and it is the only patented aspheric lens that deliberately induces controlled positive spherical aberration. That aberration spreads light along the visual axis and elongates the focal range from distance into intermediate. In practical terms, the lens stretches the focus rather than dividing it. Rayner report up to 1.5 D of increased range of focus with an emmetropic target, with contrast sensitivity and dysphotopsia levels comparable to a standard monofocal.

This is why he describes it to patients as buying range without paying an optical tax.

Is the EMV an EDOF lens?

This is a question Mr Modi is asked increasingly often, usually by patients who have read about extended depth of focus lenses and want to know whether the EMV is one. His answer is that it is — though the formal position is contested, and it is worth setting out why.

The formal definition comes from the American National Standard Z80.35-2018, which sets out four effectiveness endpoints an implant must satisfy in full before it can properly be called an extended depth of focus lens. Briefly, it must show statistical superiority over a control monofocal for mean monocular photopic distance-corrected intermediate acuity at 66 cm; it must demonstrate at least 0.5 D greater monocular depth of focus than that control at the 0.2 logMAR threshold; the median monocular distance-corrected intermediate acuity at 66 cm must reach at least 0.2 logMAR; and best-corrected distance acuity must be statistically non-inferior to the control.

The EMV does not clear all four. Non-diffractive lenses that modulate spherical aberration induce a comparatively modest amount of additional depth of focus, and for that reason they are generally described in the peer-reviewed literature as advanced, enhanced, or monofocal-plus implants rather than true EDOF lenses. Rayner themselves classify the EMV within their monofocal range, and it holds monofocal regulatory classification.

The nomenclature is genuinely contested, however, and you will encounter the lens described both ways. One published analysis argues that the EMV satisfies three of the four criteria and might reasonably be termed a non-diffractive EDOF until the standard is revisited, noting a monocular depth of focus of 1.49 D that rises to 2.25 D in a mini-monovision configuration with a 1.0 D offset in the non-dominant eye. A scoping review in BMC Ophthalmology reached the opposite conclusion, arguing that until a formal intermediate category exists these lenses are better classified as monofocal because the standard was not met in full. A more recent proposal in the Journal of Cataract and Refractive Surgery resolves the argument by giving monofocal-EDOF designs a category of their own, positioned between conventional aspheric monofocals and true EDOF lenses.

Mr Modi's position

My position is that the EMV is an extended depth of focus lens, and I think the case for saying so is stronger than the case against.

Start with the mechanism, because classification ought to follow optics rather than paperwork. An extended depth of focus lens is, by definition, one that elongates a single focal range rather than creating separate focal points. That is precisely and exclusively what the EMV does. Several lenses marketed as EDOF achieve their range through diffractive structures that split light and then blur the resulting foci into something continuous — a legitimate design, but arguably a further departure from the literal meaning of extended depth of focus than the EMV's approach of stretching one focus along the visual axis. If we are going to classify by what the optic actually does, then in my view the EMV has a better claim to the name than some lenses that already carry it.

Then consider the magnitude. The single quantitative threshold in the standard is the requirement for at least 0.5 D of additional depth of focus over a monofocal control. The EMV does not scrape past that figure; it clears it by a wide margin, with a reported monocular depth of focus of 1.49 D rising to 2.25 D in a mini-monovision configuration. A lens delivering three to four times the required increment is not a monofocal with a rounding error attached.

The criterion it fails is a monocular acuity threshold measured at a fixed 66 cm. That is a reasonable regulatory test, but it is a poor description of how the lens is used and how patients see. Vision is binocular, the EMV is frequently and deliberately implanted with a small offset between the eyes, and summation lifts real-world performance above what monocular testing at a single distance captures. Failing one distance-specific monocular endpoint tells us, I would suggest, as much about the test as about the lens.

Finally, the standard itself dates from 2018, before this class of optic existed in any numbers. It was written to regulate the diffractive EDOF lenses of that moment, and a definition drafted before a technology arrives should not be treated as a permanent verdict on it. The direction of travel in the literature supports this: one published analysis concludes the EMV can reasonably be called a non-diffractive EDOF until the standard is reconsidered, and the recent nomenclature proposal in the Journal of Cataract and Refractive Surgery creates a formal category for exactly these lenses. Rayner's own monofocal designation reflects a regulatory and reimbursement pathway rather than an optical judgement.

None of which changes what I tell you to expect, and this is the part that matters more than the label. Calling the EMV an EDOF lens does not mean it will let you read. It extends your range from distance through intermediate, and you will still need glasses for small print. The word describes the mechanism, not a promise about near vision — and I would rather you left my clinic clear about the outcome than impressed by the terminology.

What the EMV will and will not do

Mr Modi is deliberate about this in clinic, because understanding the mechanism and the expected outcome is key in choosing the right lens for each patient.

It will give you excellent unaided distance vision, and it will extend that clarity inward through the intermediate range — the dashboard, the supermarket shelf, the laptop screen, the person across the dinner table. It should not produce the night-time glare and halo phenomena associated with diffractive multifocal and spiral optics, and it holds contrast well in dim conditions, which matters for night driving.

It will not give you reading vision. You will still need glasses for a book, a phone screen, a menu in a dark restaurant, or a medicine label. Anyone who tells you an enhanced monofocal delivers spectacle independence for near is overselling it. If reading without glasses is your primary goal, the EMV is not your lens, and Mr Modi would steer you towards a trifocal or a spiral extended-depth-of-focus design instead — accepting, honestly, that some night-time halo is the trade you are making.

Comparing the options

Blended vision: getting more from the same lens

The EMV has a second use that is less well known to patients. It was designed specifically to improve on conventional monovision, giving a smoother, better-tolerated transition between the two eyes. By targeting the dominant eye for distance and leaving the second eye slightly myopic, he can extend the functional range further still, and the positive spherical aberration profile softens the mismatch that makes traditional monovision uncomfortable for some patients. Not everyone is suited to this, and it is a conversation to have at the biometry visit rather than a default setting.

It is also available in a toric version, so significant corneal astigmatism is not a barrier to using it.

Who it suits

The EMV suits the patient who drives a good deal, particularly at night; who works at a screen; who is realistic about needing readers; and who would rather protect the quality of their vision than chase glasses independence at any cost. It is also a sensible choice for eyes where a diffractive lens would be unwise — early macular change, glaucoma, previous refractive surgery, or an irregular ocular surface.

Where the EMV is available

Mr Modi implants the RayOne EMV at Nuvision Clinic in Camberley, and at Clare Park Hospital in Farnham and Mount Alvernia in Guildford. Lens choice is made after a full assessment including optical biometry, ocular surface assessment and a discussion of how you actually use your eyes day to day — not from a brochure.

Frequently asked questions

References

1. Rayner. RayOne EMV. Available at: https://rayner.com/global/en/iol/monofocal/rayone-emv/
2. American National Standards Institute. ANSI Z80.35-2018: Ophthalmics — Extended Depth of Focus Intraocular Lenses. 2018.
3. Fernández, J. et al. (2023) 'Positioning of enhanced monofocal intraocular lenses between conventional monofocal and extended depth of focus lenses: a scoping review', BMC Ophthalmology, 23:101.
4. 'Comparing an Advanced Monofocal With a Non-diffractive Extended Depth of Focus Intraocular Lens Using a Mini-Monovision Approach', American Journal of Ophthalmology, 2024.
5. 'Current and future nomenclature and categorization of intraocular lenses', Journal of Cataract and Refractive Surgery, 2024.

Arrange a consultation

Lens choice is a clinical decision made with you, not a menu selection. To discuss whether the RayOne EMV suits your eyes and your priorities, book a consultation with Mr Modi by calling 01483 901425 or email info@neilmodi.co.uk