Myopia (nearsightedness) is a condition where distant objects appear blurry while near vision remains clear.

It happens when the eye grows slightly longer than normal, or when the cornea is too curved. As a result, light focuses in front of the retina instead of directly on it.

It is one of the most common vision problems worldwide, especially in children and teenagers. 

1. Smith EL 3rd, Kee CS, Ramamirtham R, Qiao-Grider Y, Hung LF. Peripheral vision can influence eye growth and refractive development in infant monkeys. Invest Ophthalmol Vis Sci. 2005 Nov;46(11):3965-72.

2. Mutti DO, Sinnott LT, Mitchell GL, Jones-Jordan LA, Moeschberger ML, Cotter SA, Kleinstein RN, Manny RE, Twelker JD, Zadnik K; CLEERE Study Group. Relative peripheral refractive error and the risk of onset and progression of myopia in children. Invest Ophthalmol Vis Sci. 2011 Jan 5;52(1):199-205.

3. Bullimore, M. A., Saunders, K. J., Baraas, R. C., Berntsen, D. A., Chen, Z., Chia, A. W. L., Goto, S., Jiang, J., Lan, W., Logan, N. S., Najjar, R. P., Polling, J. R., Read, S. A., Woodman-Pieterse, E. C., Széll, N., Verkicharla, P. K., Wu, P. C., Zhu, X., Loughman, J., Nagra, M., … Wildsoet, C. F. (2025). IMI-Interventions for Controlling Myopia Onset and Progression 2025. Investigative ophthalmology & visual science, 66(12), 39. 

Traditional eye exams focus on central vision, but the peripheral retina also plays an important role in eye growth.

Evidence suggests that peripheral hyperopic defocus may act as a stimulus for axial elongation, thereby contributing to the progression of myopia. Conversely, inducing relative peripheral myopic defocus has been associated with slower myopia progression in children.

That is why controlling peripheral refraction is key in modern myopia management.

Axial length (AL) is a key structural indicator of myopia progression, but it is not sufficient on its own. Peripheral defocus provides critical information about retinal growth signals and helps explain, predict, and optimize myopia control outcomes.

Axial Length Reflects Outcome — Not Mechanism

Axial length is widely used because it directly measures eye elongation. However, it only shows what has already occurred and does not explain the underlying biological drivers of myopia progression. Eye growth is regulated by retinal signaling mechanisms, which are influenced by optical defocus across the retina—especially in the peripheral region.

Peripheral Defocus Reflects Retinal Growth Signals

Peripheral defocus describes how light is focused on the retina outside the central visual axis. Peripheral hyperopic defocus → associated with increased axial elongation Peripheral myopic defocus → associated with slowed eye growth.

This forms a biological pathway: Peripheral Defocus → Retinal Signal → Eye Growth → Axial Elongation

Value of Combining Axial Length and Peripheral Defocus

Axial Length → measures structural progression

Peripheral Defocus → reflects retinal signaling

Combined, they enable:

Better risk assessment Personalized treatment design Improved prediction of progression​​​​​​​

1. Leighton RE, Breslin KM, Richardson P, Doyle L, McCullough SJ, Saunders KJ. Relative peripheral hyperopia leads to greater short-term axial length growth in White children with myopia. Ophthalmic Physiol Opt. 2023 Sep;43(5):985-996. doi: 10.1111/opo.13185. Epub 2023 Jun 20. PMID: 37340533.

2.Ma JX, Tian SW, Liu QP. Effectiveness of peripheral defocus spectacle lenses in myopia control: a Meta-analysis and systematic review. Int J Ophthalmol. 2022 Oct 18;15(10):1699-1706. doi: 10.18240/ijo.2022.10.20. PMID: 36262865; PMCID: PMC9522561.

​​​​​​​3.Yamaguchi T, Ohnuma K, Konomi K, Satake Y, Shimazaki J, Negishi K. Peripheral optical quality and myopia progression in children. Graefes Arch Clin Exp Ophthalmol. 2014 Jan;252(1):175. doi: 10.1007/s00417-013-2507-0. Epub 2013 Nov 20. PMID: 24253497.

​​​​​​​4.Kubota R, Joshi NR, Samandarova I, Oliva M, Selenow A, Gupta A, Ali SR. Effect of short-term peripheral myopic defocus on ocular biometrics using Fresnel "press-on" lenses in humans. Sci Rep. 2021 Nov 22;11(1):22690. doi: 10.1038/s41598-021-02043-2. PMID: 34811408; PMCID: PMC8608875.

In the 1930s Ferree et al. pioneered the measurement of peripheral refraction by modifying a Zeiss parallax refractometer and mounting it onto a rotatable carriage enabling measurements along the horizontal meridian from temporal 60° to nasal 60°.

In 1971, Hoogerheide and Rempt  investigated the relationship between myopia and peripheral refraction in pilots using a retinoscope. This involves framing positive and negative lenses on a rotatable disc, which is placed in front of each eye of the subject. The examiner selected the appropriate lens based on the motion of the retinoscopic shadow until a neutral state was achieved.

In 1977, Jennings and Charman introduced a double-pass photo-electric ophthalmoscopic method to objectively study the variation in image quality across the retina by analyzing the reflected image of a fine line, known as the line spread-function.

In 1998, Navarro et al. utilized a laser raytracing method to investigate the monochromatic aberrations of the human eye along the temporal meridian. This method involved directing a narrow laser beam into the eye through a specific point on the pupil and capturing the aerial image of the retinal spot with a CCD camera.

Peripheral refraction measurement with Shack Hartman aberrometer were performed by David  in 2007 and Linda  in 2009.

In recent studies, the open-field refractor is commonly used by researchers, such as the SRW500010 /SRW500111 (Ajinomoto, Japan), NVision K-500112 (Shin-Nippon, Japan) and WAM-550013 (Grand-Seiko, Tokyo, Japan).

Traditional Peripheral Refraction Measurement methods have limitations: time-consuming, limited measurement points, requires significant patient cooperation,less practical in routine clinics. This makes full peripheral mapping difficult in daily practice.

Unlike conventional techniques for peripheral refraction measurement, Refraction Topography (RT) enables the simultaneous measurement of refraction for spatially distributed points. The method features a single fixation target and captures dozens of fundus images allowing for the measurement of millions of points in seconds.

1. Smith EL 3rd, Kee CS, Ramamirtham R, Qiao-Grider Y, Hung LF. Peripheral vision can influence eye growth and refractive development in infant monkeys. Invest Ophthalmol Vis Sci. 2005 Nov;46(11):3965-72.

2. Mutti DO, Sinnott LT, Mitchell GL, Jones-Jordan LA, Moeschberger ML, Cotter SA, Kleinstein RN, Manny RE, Twelker JD, Zadnik K; CLEERE Study Group. Relative peripheral refractive error and the risk of onset and progression of myopia in children. Invest Ophthalmol Vis Sci. 2011 Jan 5;52(1):199-205.

3. Bullimore, M. A., Saunders, K. J., Baraas, R. C., Berntsen, D. A., Chen, Z., Chia, A. W. L., Goto, S., Jiang, J., Lan, W., Logan, N. S., Najjar, R. P., Polling, J. R., Read, S. A., Woodman-Pieterse, E. C., Széll, N., Verkicharla, P. K., Wu, P. C., Zhu, X., Loughman, J., Nagra, M., … Wildsoet, C. F. (2025). IMI-Interventions for Controlling Myopia Onset and Progression 2025. Investigative ophthalmology & visual science, 66(12), 39. 

open-field refractor

Refraction Topography

Refraction Topography (RT) enables the simultaneous measurement of refraction for spatially distributed points. The method features a single fixation target and captures dozens of fundus images allowing for the measurement of millions of points in seconds

Instead of one central value, Refraction topography provides a “visual map” of refractive status across different retinal zones. Visually displays the defocus profile of the eye, helping both patients and clinicians better understand the spatial distribution of defocus:

where defocus occurs?   how strong it is?   how it changes across the eye?

1. Yequan, H., Jingyun, G., Yu, G. et al. A focusing method on refraction topography measurement. Sci Rep 13, 16440 (2023). 

Orthokeratology (OK) lenses are a well-established intervention for controlling myopia progression in children and adolescents. By reshaping the corneal surface, OK lenses induce relative peripheral myopic defocus on the retina, which is believed to slow axial elongation.

Using wide-angle Refraction Topography, peripheral defocus can be quantitatively assessed across a 150° visual field in children wearing OK lenses. This approach enables, for the first time, a complete horizontal characterization of the myopic defocus ring, including its spatial distribution and morphological parameters.

Clinical findings demonstrate that OK lens wear induces significant peripheral myopic defocus. Notably, a wider defocus ring, a position closer to the macular region, and a greater magnitude of relative peripheral myopic defocus are all associated with reduced axial elongation. Furthermore, when combined with patient age and baseline axial length, these peripheral defocus parameters show predictive value for myopia progression.

1. Mandantuoya, Ao M, Zhang Y. The relationship between relative peripheral refraction and axial length elongation in myopic children wearing orthokeratology lenses using a novel wide-angle multispectral refraction topographer. Cont Lens Anterior Eye. 2025 Oct 13;102517. doi: 10.1016/j.clae.2025.102517. Epub ahead of print. PMID: 41087277.

Personalized myopia control integrates peripheral refraction profile data to enable customized lens design and treatment strategies.

The free-form rear surface is customised with the subject's baseline peripheral refraction measured by refractive topography (RT), which tends to compensate for or correct the original peripheral refraction.

The goal is simple: slow down myopia progression in a way tailored to each patient.

1. Lei S, Wu Y, Kou J, Chen Q, Liu L. The effect of individualized ocular refraction customized spectacle lenses on myopia control in schoolchildren: A 1-year randomised clinical trial. Ophthalmic Physiol Opt. 2024 Sep;44(6):1279-1289