A narrative review of 26 independent studies of children wearing highly aspherical lenslet technology (HAL) lenses for at least six months has concluded that these lenses appear to be effective at slowing axial elongation and progression in myopic children.1
Additionally, the review found that, regardless of study design and location, axial elongation in children wearing HAL lenses was substantially lower than in those wearing single vision lenses. HAL technology is used in Essilor’s Stellest lens.
Published in Optometry and Vision Science, the review was supported by EssilorLuxottica and conducted by Olga Prenat, Global Head, Medical and Professional Affairs at EssilorLuxottica and Professor Mark Bullimore, of the University of Houston. They searched both PubMed and Scopus in December 2025 using the terms: (myopi*) AND (child* OR adolescen*) AND (aspherical lenslets OR Stellest OR high aspherical lenticule). From the 78 papers identified as discussing HAL lenses, they extracted data including study duration, mean age, mean myopia progression, and mean axial elongation.
While many of the papers reported vision or choroidal changes, or were review articles, 26 independent studies reported myopia progression, axial elongation, or both, for children wearing HAL lenses for at least six months. Seventeen of these studies were conducted in China. The studies varied widely, with four randomised clinical trials, six prospective studies, and 16 retrospective studies.
Some studies compared children wearing HAL to more than one medium. Eleven compared children wearing HAL to children wearing single vision lenses (mean age 10.2 years), eight compared HAL to other myopia control spectacles, and 10 compared HAL to overnight orthokeratology. Five studies reported on HAL lenses worn in combination with atropine.
Collectively, the studies reported on 4,079 children wearing HAL lenses and all but two studies reported on changes in axial length.
Findings
In the comparison with single vision lenses, the median one-year axial elongation for HAL wearers was 0.12 mm compared with 0.32 mm in the single vision group.
When comparing HAL with other myopia control spectacles, they reported both HAL and defocus incorporated multiple segments (DIMS) used in HOYA MiyoSmart, “slowed progression by 0.30 D, but HAL wearers showed less myopia progression (0.14 D) than the DIMS wearers”. However, the authors also observed that other studies had “found no difference between HAL and DIMS spectacle lenses”.
Among 10 studies comparing children wearing HAL to children wearing overnight orthokeratology, six showed slower axial elongation for HAL lenses in at least one subgroup. The authors wrote, “Axial elongation in children wearing HAL lenses is similar to those fitted with overnight orthokeratology lenses and slower in some studies, with these differences more apparent in children with lower levels of myopia.”
In studies of children wearing HAL lenses in combination with atropine, atropine increased the effectiveness of HAL lenses and vice versa.
All mean axial elongation values for children wearing HAL lenses were below those for untreated children.
Considerations
The authors concluded that “Based on a large body of literature from multiple countries, HAL lenses appear to be effective at slowing axial elongation and progression in myopic children.”
However, they cautioned, “The majority of the studies discussed in this narrative review are retrospective and thus represent lower quality evidence. Likewise, most studies are only one to two years in duration and additional high-quality randomised trials are still needed to strengthen certainty”.
Reference
- Prenat O, Bullimore MA. Slowing of myopia progression by spectacles with highly aspherical lenslets – A narrative review. Optom Vis Sci. 2026;103(9):e70096. doi: 10.1002/ovs2.70096.
