Once upon a time, a researcher from the Center for Myopia Research at the School of Optometry from Poly U in China was investigating different ways to counteract myopia progression. Data from around the world indicated that the prevalence of myopia was growing exponentially and if nothing was done to reduce the rate, patients could experience severe complications such as retinal detachment or other eye diseases.

Dr Chi-ho To was in the midst of discovering new technologies for his latest research. He was leaning towards certain resources and white papers detailing current myopia control methods such as environmental, pharmacological and optical.

One day, he was commuting by bus on the way to work. As he sat on the bus, he looked outside. To his surprise, the bus had window clings (window shades) allowing people inside the bus to see outside, but not the other way around.

Being a myopic patient himself, he removed his glasses to see through the little holes that the window clings had and to his surprise, he could see clearly with a very acceptable visual acuity.

From his literature assessment, he reviewed the different optical alternatives available to help the slowdown of the myopia. Some studies were talking about the usage of PAL (COMET study in 2001), Ortho-K (Romio study, Cho & Cheung, 2012), correction of peripheral refraction (Sankaridurg et al. 2010) but there was nothing about Optical Defocus. In many animal models, optical defocus drives eye growth. From his experience with the window cling on the bus, and the findings from his recent literature review, he concluded that a way to control myopia could be in combining 2 stimuli, one with minus power and another one with plus power.

That is when some testing started with different formulas. A study was conducted to test with +10.00 and -10.00, to ensure that there is a simultaneous presentation of myopic defocus (MD) and hyperopic defocus (HD). In order to put both Rx in the same lens, he did not want to have a design that is apparent to what we see in a PAL, the design had to be on the whole surface of the lens.

In the initial testing, the study split both powers in a 50:50 split. Testing was significantly conclusive where a dual power lens combined with a 50:50 split caused a reduction in the myopia progression. In the same study, they tested different ratios (33:67, 25:75 & 0:100). The study performed by Tse et al. in 2007, showed the results.

The problem was that these studies were done on animals. How can the human eye react to this type of design?

There was a randomised clinical trial done in Hong Kong with children to test the Defocus Incorporated Soft contact lenses. One of the major contact lens manufacturers was using the base of this technology for their myopia control contact lens. The DISC technology would provide a clear central vision and constant myopic defocus in front of the retina simultaneously. Part of the conclusion was that myopic defocus could slow down myopia progression in children (Lam C S Y et Al. 2013).

Then the challenge for Dr. To was to take a look at the DISC technology and see how they can incorporate it into an ophthalmic lens. The key thing to remember was that the Optical defocus had to be present at all areas of the lens.

After absorbing all the data from the literature review, he worked on a model that would use a defocus lens design to provide a distant Rx and myopic defocus in a simultaneous presentation. This would override the eye movement that we experience while we wear glasses (versus contact lenses), with a stable vision of near and distant vision with myopic defocus (“acceptable blurriness”).

This is where the honeycomb idea came into play. Using micro-lenses of +3.50D for projecting myopic defocus while having a 50:50 ratio of these micro-lenses all around the lens. This is how the creation of Defocus Incorporated Multiple Segment (DIMS) occurred; the rest is history!