About Us General Research Landscape Research Cases Research Funding Schemes Common Tips for Application Career Development
About Us General Research Landscape Research Cases Research Funding Schemes Common Tips for Application Career Development

Defocused Incorporated Multi-Segment (DIMS) Spectacle Lens

30% of the world’s population are short-sighted! This new invention may reduce the myopia population and has won international awards!

Deep myopia causes life challenges for many individuals and even increases the risk of other types of eye diseases. In recent years, a Hong Kong research team has successfully developed a new non-invasive solution in the form of an invention, which can slow down myopia progression in children. It has even reversed the myopia in some individuals. This internationally award-winning invention is a piece of welcome news for short-sighted children!


About the DIMS Lens

Defocused Incorporated Multi-Segment (DIMS) Spectacle Lens
A lens slowing down progression of myopia that won multiple international awards

The research team led by Professor Carly Lam, Professor of the School of Optometry at The Hong Kong Polytechnic University (PolyU), and Professor To Chi-ho, Chair Professor of Experimental Optometry, Henry G. Leong Professor in Elderly Vision Health and Head of the School, developed the Defocus Incorporated Multiple Segments (DIMS) spectacle lens, which incorporated myopic defocus into a conventional visual correction lens. The DIMS lenses effectively slowed down myopia progression by 60% while more than 20% of the short-sighted children that participated in the clinical trial did not have any myopia progression.
The DIMS lens won the Grand Prize (overall championship), a Grand Award and a Gold Medal receiving the Congratulations of the Jury at the 46th International Exhibition of Inventions in Geneva, Switzerland in 2018 and the 2020 SILMO d’Or Award (Vision) in the prestigious SILMO optical fair in France.
Before introducing the DIMS lens, let’s learn about its journey!

(From left to right) Professor Carly Lam, Professor of the School of Optometry and Professor To Chi-ho, Chair Professor of Experimental Optometry, Henry G. Leong Professor in Elderly Vision Health

(From left to right) Professor Carly Lam, Professor of the School of Optometry and Professor To Chi-ho, Chair Professor of Experimental Optometry, Henry G. Leong Professor in Elderly Vision Health


The first of its kind in the world

Before the launch of the product, Professor Lam and Professor To’s research team conducted research and a series of tests on animals and human to verify their hypothesis. They first conducted experiments through one type of animal before extending the trial to mammals and humans. Can you guess what type of animal they tested on at the start?

Birds Fishes Insects

Correct answer: Birds。
The research team was the first group in the world that tested their hypothesis on avian animals (birds), mammals and then on humans over the clinical trial process.


DIMS lens is now a commercially available product.

Can you guess how many countries or regions have DIMS lens on sale?

Between 3-5 countries or regions Over 10 countries or regions Over 30 countries or regions

Correct answer: Over 10 countries or regions。
Over 10 countries or regions! DIMS lens is now commercially available in Hong Kong and other countries and regions, including China, Singapore, Malaysia, Canada, France, Australia, United Kingdom, Italy, Russia etc.

DIMS lens

The DIMS lens has been adopted far and wide since its launch.

Can you guess how many DIMS lens have been sold in just the first three years?

200,000 pieces 400,000 pieces 1,280,000 pieces

Correct answer: 1,280,000 pieces。
Since the launch of DIMS lens in July 2018, 1,280,000 pieces have been sold in the first three years.

Can you guess how many DIMS lens
Prev Next

About myopia

Myopia is not just an inconvenience, I is also associated with poor education progress, limited career progress, increased risk of accidents such as falls, loss of productivity and consequently a reduction in quality of life at different stages of life. Around 40% of Hong Kong schoolchildren have myopia and the condition accelerates in adolescence so almost 80% of students require glasses or contact lenses to correct their vision by the time they reach university.

Over the last three decades, in many parts of East and Southeast Asia, 70 to 80% of young adults are myopic, and as many as 20% of children are highly myopic, with refractions worse than -6.00D.
Recent studies show that myopia is not just a problem among Chinese and South-East Asians. In 2000, it was estimated that there were 1.4 billion people with myopia (22.9% of the world population) and 163 million people with high myopia (2.7% of the world population).
By 2050, it is estimated there could be 4.7 billion people with myopia (49.8% of the world) and 938 million people will suffer from high myopia (9.8% of the world).

What is myopia?

In a normal eye, images focus accurately on the retina (the back part of our eyes). In an eye with myopia (a myopic eye), the eyeball is either too long or the cornea is too curved causing the image to focus in front of the retina. Hence, objects far away cannot be viewed clearly appear blurry while near objects remain visible.

Normally, our eyes can distinguish between clear and blurred images. The developing eye has a natural homeostatic mechanism – the eyeball size regulates in order to receive a clear image. "Myopic defocus" allows it to focus the image on the front of the retina. Through the natural homeostatic mechanism, the eyeball will shorten in length to receive a clear image. This method also sends a “STOP” signal to halt any excessive growth of the eyeball. The team’s studies between 2007-2014 confirmed that such myopic defocus effectively inhibits axial elongation in several animal species, including chicks, guinea pigs and monkeys.

The team applied the findings to the lens design. The principle is to produce a clear image on the retina and a defocused or blurred image in front of the retina simultaneously. In this way, the wearer of the lens can enjoy a clear and comfortable vision while the blurred image created by the defocus helps to control the growth of the eyeball so that the myopia progression is controlled.

The DIMS lens comprises a central optical zone for correcting the refractive error (i.e. myopia and astigmatism) and multi-segments of constant myopic defocus surrounding the central zone extending to the mid-periphery of the lens. This design enables the wearer to receive myopic defocus in all directions of a gaze.

In a two-year clinical trial commencing in 2014, 180 short-sighted school children aged between 8 and 13 were recruited. Half of them were randomly assigned to wear DIMS lenses and the rest of them were in a control group wearing regular single vision lenses.

During the two-year trial, their eyes were checked every six months. By the end of the trial, those in the DIMS group showed an average myopia progression of -0.38 while the progression for the control group was -0.93 on average.

The DIMS lenses effectively slowed down myopia progression by 60%.
Within the DIMS group, 21.5% of the subjects did not have any myopia progression at all while the figure was only 7.4% in the control group.

The trial demonstrated that the DIMS lens can helpthe wearer control myopia progression effectively through this non-invasive solution. No limitations were imposed on the age of wearers, ensuring that more people can benefit from this invention.

Listen to the introduction by Professor Carly Lam and Professor To Chi-ho to learn more:

Prev Next

The impact on our lives and on society

Reducing myopia progression at a young age can significantly reduce the chance of suffering severe visual impairment and blindness due to high myopia in later life. Myopia control is currently possible through optical or pharmaceutical approaches.

This optical approach – being less invasive – is preferable. Research and innovation is changing clinical practice in myopia control for children and will, in the long run, reduce the burden of visual health cost both at an individual level and at a societal level.

Twenty years ago, the cause of myopia was a matter of controversy and the ability of managing it in a clinical manner was a hit or a miss. Through the team’s efforts, they validated and proved their hypothesis on the visual modulation of eye growth. This research has achieved a breakthrough and will make an impact in different ways.

Click on the keywords below to learn more!

The first one of its kind in the world

Professor Lam and Professor To’s research team is the first group in the world that has the record of testing their hypothesis across avian (birds) animals, mammals and then to humans within a clinical trial setting.

>10 countries and regions

The DIMS lens is now commercially available in more than 10 countries and regions, including Hong Kong, China, Singapore, Malaysia, Canada, France, Australia, United Kingdom, Italy and Russia etc.

>25 organisations

The team proposed principle of adopting simultaneous vision correction and myopic defocus for myopia control is now widely accepted by peers in the field of myopia research. Their work has extended collaboration to over 25 research institutions. Their translational lenses received high regards from clinicians fitting the lenses and has influenced clinical practice with evidence-based research.

>75,000 practicitioners

Over 3,000 seminars in Hong Kong, the Mainland and other countries have been organized, attracting more than 75,000 practitioners to attend workshops, seminars and talks since the launch of the DIMS Lens in 2018. The team foresaw significant demand from Asian countries, including Singapore, Malaysia and Korea.

>1,280,000 pieces

Around 1,280,000 pieces of DIMS Lens have been sold in the first 36 months since its launch in July 2018

Non-invasive intervention

As the eyeball develops rapidly from early childhood to adolescence, progression of myopia is the fastest during this period. This is also a key period for myopia treatment. Compared with using atropine or orthokeratology, the DIMS lens is a non-invasive intervention and hence there is no age limitation and can even benefit young children.

The team anticipates that many children will no longer suffer from high myopia and will not suffer from visual impairment or blindness cause by high myopia growing up. In such scenarios, their risk of suffering from other eye diseases and the economic burden caused by the illness will also be reduced benefiting their whole life.

Reducing social burden

The epidemic of myopia in the ageing myopic population will impose an excessive burden on the overburndened public healthcare systems. Numerous types of costs are associated with its impact including the cost of myopia corrections, public ophthalmologic services, training extra optometrists and ophthalmologists, the social welfare cost for caring the vision impaired, cost of accidents such as falls due to visual impairment as well as loss of productivity due to vision impairment. Prevention of high myopia, in turn, will reduce the number of people suffering from myopia-related vision impairments and therefore alleviate the burden on the public healthcare system.


International recognition received by the DIMS lens

Recognition from the Government of the HKSAR

DIMS lens received supported from different funding agencies under the Government of the HKSAR, including the Research Impact Fund from Research Grant Committee, and Health@InnoHK from Innovation and Technology Commission.

In June 2018, the Government held a CE's Reception for Awardees of International Exhibition of Inventions of Geneva 2021 to commend Hong Kong research and development (R&D) talent for inventions that won worldwide acclaim.

Prev Next

“Passion in your work and belief in yourself are the core drives for us. Despite many ups and downs, we stuck to our goals we set to realise our dreams.”

Professor Lam's encouragement to young researchers