Optimizing distance vision with MiSight 1 day

Contact lens wear is beneficial for the confidence of children and teens, and myopia controlling contact lenses have the benefit of both correcting and helping control myopia. Research has shown that 85% of 8- to 12-year old children new to contact lens wear are able to easily handle daily disposable lenses after a month of wear, and the safety profile is high, with rates of microbial keratitis (MK) or inflammatory complications no higher when compared to adults.¹

The CooperVision MiSight® 1 day is a daily disposable contact lens designed for the sole purpose of myopia control in children. In November 2019 it was the first contact lens, and first myopia control intervention, to be given United States FDA approval for slowing myopia progression in children aged 8 to 12 years with -0.75 to -4.00D spherical equivalent myopia and <0.75D astigmatism at commencement of treatment.

As the MiSight 1 day contact lens is different from a standard single vision contact lens in its dual-focus design, the vision experience may vary between patients. KS shared this question with the Myopia Profile Facebook community in this post about a patient experiencing blurred distance vision with MiSight 1 day contact lenses.

As there are four concentric optical zones in MiSight 1 day lenses (2 distance vision correction zones and 2 treatment zones with +2.00D of defocus), vision may be affected if the patient is not looking through the correction zone, a likely occurrence if the lens is significantly decentered. Lens centration can be assessed with slit lamp biomicroscopy, topography or retinoscopy, where a loose fitting lens (more than 0.5mm movement with blinks) could affect vision. In the MiSight 1 day clinical study, only 6 out of 144 children showed unacceptable lens fit and did not proceed – three wearing MiSight 1 day and three wearing the control single vision lens.²

Some commenters suggested adjusting the prescription ±0.25D to improve distance vision. The MiSight 1 day fitting guide suggests increasing minus in 0.25D steps only if it significantly improves distance vision or reduce minus in 0.25D steps ensuring no decrease in acuity and no subjective visual impact, to avoid over-minusing.

In a presentation at the NCC-BCLA 2020 online conference, Logan et al presented additional data from the ongoing MiSight 1 day clinical trial, which showed that almost 70% of MiSight 1 day fits require no over-refraction adjustment from their best-vision sphere starting power for trial lens fitting. Approximately 20% required 0.25D or less than 0.50D of adjustment over the suggested lens power, with the 10% remainder requiring more than 0.50D over-refraction.³ The MiSight fitting guide suggests only adding extra minus if it improves distance vision.

The dual-focus optical design of MiSight 1 day may be more challenging to adapt to than a single vision lens. Some of the commenters raised the observation of initial adaptation in the first week of wear. The MiSight 1 day fitting guide mentions that "under certain circumstances (such as low light levels), this optical design can cause reduced image contrast, symptoms of ghost images, and/or glare or halos around bright lights."

Some children may require an adaptation period to both contact lens comfort and vision, as do adults. After initial fitting, it is important to re-assess children new to contact lenses to check vision and eye health outcomes. The International Myopia Institute Clinical Management Guidelines recommend follow up 4-7 days after initially fitting myopia controlling soft contact lenses. This is a useful time frame over which to encourage a patient noticing initial ghosting, halos or glare at fitting to persevere with adaptation.

Indeed, a 2019 research abstract⁴ indicated when children in the MiSight 1 day clinical trial were asked 'how well do you see with your CLs for school', almost all gave a rating of 'really well' or 'kind of well'. The time frame on visual adaptation was not described, but when the children were asked "how much they noticed ghosting, hales or glare, over 90% all subjects reported 'not noticeable'/'not annoying' visual disturbances; 10% of [MiSight 1 day] subjects reported 'slightly annoying' ghosting compared to 5%" [of single vision Proclear 1 day wearers]. It was reported that this higher frequency of mild visual symptoms in children wearing MiSight 1 day did not affect their wearing time, and only one clinical trial participant out of 70 discontinued the dual focus lens design wear due to vision.

The MiSight 1 day three year clinical trial found that best corrected acuity with MiSight 1 day was within one letter forthe dual focus lens and the control (single vision) lens at distance and near, with a mean of around 0.00 logMAR (6/6 or 20/20) or better in both lens types.²

1. If your patient experiences blurred distance vision with MiSight 1 day lenses on fitting, check the lens centration and fit, and if any over-refraction is required.
2. New wearers may also notice ghost images, halos or glare with MiSight 1 day, particularly under low illumination conditions. It is best to advise patients of this possibility. Explain that these symptoms are usually mild and reduce or resolve on adaptation, and review again after 4-7 days.

FDA Indications for use (US only): MiSight® 1 day (omafilcon A) soft (hydrophilic) contact lenses for daily wear are indicated for the correction of myopic ametropia and for slowing the progression of myopia in children with non-diseased eyes, who at the initiation of treatment are 8-12 years of age and have a refraction of -0.75 to -4.00 diopters (spherical equivalent) with ≤0.75 diopters of astigmatism. The lens is to be discarded after each removal.