A Better Single Vision Solution for Young Eyes

Optical Technology Product Spotlight: ZEISS SmartLife® Young Single Vision lenses

Learning Objectives:

Upon completion of this course, participants will be able to:

  1. Explain the unique vision challenges for children and teens wearing eyeglasses, as their vision needs, and bodies change with age.
  2. Describe the unique visual challenges facing children and teens when using eyeglasses to view digital devices, especially smartphones.
  3. Describe the unique visual challenges as kids and teens frequently switch viewing distances in their lenses.
  4. Explain the definition of 'Phygital'.

Faculty/Editorial Board

Deborah KotobDeborah Kotob, ABOM, is the Director of Education and Training for Jobson Medical Information and the Director of 20/20 Magazines Pro to Pro. Her experience spans more than twenty years in the optical industry. During this time, her roles included optical boutiques owner, optician, optical frame sales, and over ten years in lens manufacturing as a Lens Consultant, Trainer, and LMS content developer. She lectures, trains, conducts webinars on a variety of optical and practice development topics.

Credit Statement

This course is approved for one (1) hour of CE credit by the American Board of Opticianry (ABO). One-hour, Ophthalmic Level 2, Course # STWJHI075-2,


This course is supported by an educational grant from ZEISS.

By age 6, full emmetropization occurs, with some eyes developing normally and others developing ametropia (myopia and hyperopia). Opticians are accustomed to fitting young ametropes in stock single vision lenses. But this one-size-fits-all approach does not address the unique vision challenges of today's young ametropic digital natives ages 6 through 19. This group is underserved when dispensed stock single vision lenses because the lenses will not accommodate age-related anatomical changes, such as pupil size, pupillary distance, etc. Yet, age-dependent changes in pupil size and pupillary distance combined with viewing distance and other parameters impact the clarity and comfort experienced in single vision lenses. Just as we understand the need for impact resistant materials to protect young eyes, in this course, we will learn that kids and teens need single vision lenses designed for their age and evolving "phygital" (combination of physical and digital) visual needs. Read on to learn about a better single vision solution: ZEISS SmartLife Young Single Vision lenses provide this age group with a better single vision solution with a design that optimizes the lens optics to suit their age-based vision needs.

Across the world and all age groups, digital devices are a significant part of everyday life. From an early age, the digital environment becomes integral to educational and social activities in a child's daily life, producing a multi-cognitive online/offline generation. Today's youth play, learn and communicate using smart digital devices and technologies like augmented reality. Therefore, the phygital world (a combination of physical and digital worlds) becomes more immersive and relevant, especially for kids and teenagers.

In a recent survey, parents were asked how their children (age 12 years and younger) engage with digital devices. Sixty percent of parents say their children began using smart- phones before age 5.2 Additionally, studies from 2019 conducted in the U.K. found that between 8 and 11 years, 93 percent of chil- dren go online for nearly 13.5 hours a week, and 18 percent already have a social media profile. While in the group between 12 and 15 years of age, 99 percent go online for almost 20.5 hours a week, and nearly 69 per- cent have a social media profile.3

Apart from the increasing time today's youth spend in front of digital devices, they also routinely spend time outdoors playing sports or meeting with friends. When asked how much time children spent outdoors, in a survey of 1,450 households, the average time children spent outdoors was reported as at least two hours outdoors daily.4 Another study conducted in the U.S. on 1,200 households found that children aged between 2 to 10 years spend an average of 19 hours per week using digital devices while spending 11 hours per week playing outdoors.5 This data illustrates the need for comfortable vision for the extended hours young eyes spend switching viewing distances.

In addition to the visual challenges facing our youth in their phygital world, their growing bodies undergo substantial anatomical and physiological changes during this stage of life. Their arm span increases, and their facial anatomy changes, impacting the viewing distances and position of wear parameters.

Yet, children routinely receive stock lenses not explicitly designed for their age-related visual needs or their digital and outdoor lifestyles. Nor are they designed for their age-related position of wear parameter. Therefore, they are a compromise in visual comfort and cosmetics. Kids and teens have a connected and active lifestyle, which must be considered along with their anatomical changes in the lens design calculation to produce the best vision performance for every situation, all day.

Anatomical and physical properties impact the viewing distance of the lens wearers. Handheld digital devices require our hands for control and arms to hold the device at an appropriate length. The physical growth of the arms may be an influencing factor to an increasing viewing distance during the growth phase of younger age groups. The mean arm span length of 8-year-old boys and girls is 127.1 cm compared to 175.5 cm at 18.6 When viewing device screens, we are most comfortable with our arms and elbows close to the body and our hands positioned close to the torso and below the head. A recent five-year study showed that users of handheld devices must bend the upper spine and tip the head forward to adapt to this position. But bending the neck forward still requires downward eye rotation to view our smartphone screen. A recent ZEISS research study showed that spectacle wearers using smartphones turn their eyes to look lower through their lenses, including when performing deskwork, in conversation and while walking. One consequence of this change is that wearers use a larger area of their lenses for a broader range of visual fixations.

A ZEISS study of adults in 2019 showed that visual behavior changes when people are connected and on the move. A ZEISS study on visual behavior found that eyeglass wearers using smartphones look through the lens' lower area. This behavior was found during desk work, conversation and walking while viewing a smartphone. As a result, wearers use a larger lens area for visual fixations because eye movements shift significantly downward when using a smartphone.

Various studies researched viewing and reading distance relative to digital device use in younger age groups.

The graph in Fig. 2 shows the age-related increase of the viewing distance beginning at age 6 with 20 cm and indicates a constant value at age 20 with 30 cm.7, 8, 9, 10 Therefore, we can conclude that an increased viewing distance is associated with the age-dependent increase in arm length.

Facial anatomy and shape impact the Position of Wear (PoW) parameters and consequently, the lens' optical performance. The human face has fixed anatomical features like eyes, nose, lips and chin. But our facial characteristics change throughout our entire lifetime, especially at younger ages (Fig. 3).

Fig. 4 shows the facial growth changes between 7 to 17-year-old girls and boys (colored upper row). The blue-shaded areas on the grey facial images (second and fourth row) indicate locations of significant differences. On average, the most substantial changes occur between the ages of 7 and 14 (girls ages 7 to 13 and boys ages 11 to 14). Between 14 and 16 years of age, the area around the eyes became deeper relative to the facial plane.12 Another facial anatomical change in this age group is the increasing interpupillary distance (PD). A recent study of 1,311 subjects ages 1to 19 stated a mean PD of 42 mm at one year and 62 mm at age 19.13

Fig. 6 shows that the pupil size grows until age 20 anddeclines afterward.15

Pupillary distance (PD) is essential in ensuring pupils align with the optical center of the lens. ZEISS analyzed and evaluated 1 million data points in children's PoW parameters from individual order data from 2020 to 2022. The data of the PD values are consistent with the study findings on age-related facial changes (Fig. 5).

Besides PD and fitting height, distance between lenses (DBL) and frame box data showed significant differences between the considered age groups. These findings are incorporated into the age-related lens design calculation, as is the age-dependent viewing distance.


The pupil controls the size of the beam and light intensity entering the eye. The pupil changes with age, changing how much incoming light reaches the retina—the larger the pupil's diameter, the larger the incoming light beam. Both pupil diameter and beam size are age and light-dependent. These changing properties can affect retinal illuminance and depth of focus, making pupil diameter a vital consideration when optimizing lenses. A study conducted in 2015 of 272 participants in the age group 1 to 18 years shows that the maximum average pupil size (low light conditions) at one year is 4.82 mm compared to the age of 16 years of 6.01 mm. Under bright light conditions, the difference was 3.44 mm at the age of 1 year compared to 3.92 mm at 16 years.14 Another study investigated the pupil size while reading digital and print media. While reading on digital devices, the lig ht emitted from the screen can reduce pupil size by up to 20 percent compared to print media.16 The study results indicate the need to consider light conditions' effect on pupil size, ensuring the best visual performance.

ZEISS SmartLife Young Single Vision lens design optimizes lenses specifically for young people, compensating for their position of wear parameters and age-based viewing distance, pupil size, PD and visual fixations to accommodate their conne cte d lifest yle and changing anatomy.


The diagram in Fig. 7 is an overview of the SmartView technologies integrated into ZEISS SmartLife Young Single Vision lenses.

ZEISS SmartView 2.0 technology is adapted for young eyes. ZEISS Smart-View 2.0 technology was launched with ZEISS SmartLife lenses for adults (age 20 years and older) and is the basis for ZEISS SmartLife Young Single Vision lenses optimized for the visual needs and requirements of ages 6 to 19 years.

ZEISS Smart Dynamic Optics now considers viewing distances of the young age group. ZEISS Smart Dynamic Optics considers the correlation between the viewing angles and object distances for sharp vision at all distances, particularly when lowering the gaze to focus on close objects for their connected and active lifestyle. Smart Dynamic Optics (3D object-space-model) has been adapted to the age-related viewing distance. The object space model minimizes oblique astigmatism when wearers look down to view a close handheld device and when they look up to see more distant objects. The design optimization makes the change as smooth and imperceptible as possible (Fig. 7).

Due to anatomical differences, children have different viewing distances than adults when, for example, they are using smartphones. The viewing distance between a child's and an adult's eye increases from 20 to 30 cm. Therefore, the 3D object-space model based on an adult's viewing distance has been adapted to a child's age-related viewing distance. Based on the age provided on the lens order, the value of the age-related viewing distance is considered individually for the 3D object-space model (Fig. 8).

ZEISS Age Intelligence: Age intelligence is the enabler for two technologies for ZEISS SmartLife Young Single Vision lenses: ZEISS Luminance Design 2.0 technology has been adapted to consider the increase in pupil diameter from ag es 6 to 19. Smart Dynamic Optics ensures their glasses fit their dynamic visual behavior. As a part of the ZEISS SmartView 2.0 technology, Age Intelligence delivers the age parameter for ZEISS Luminance Design 2.0 technology and ZEISS Dynamic AgeFit technology.

ZEISS Luminance Design 2.0 technology: Pupil diameter increases until age 20, with significant changes from 1 to 19 years. Therefore, ZEISS Luminance Design 2.1 technology considers the wearers' age-related pupil size for the lens calculation to achieve the best possible optical performance of the lens. A default value is used if the age is not provided on the order.

ZEISS Dynamic Age Fit technology: Studies and internal data show that children's PD has a dynamic age-related change, as do frame height or B measurement and distance between lenses (DBL). ZEISS Dynamic AgeFit technology has been developed specifically for this age group. It considers the age-related changing PoW and frame parameters for the best optical performance depending on the wearer's age. Dynamic AgeFit technology adapts the SmartLife® Young lens design to their smaller faces and frames (Fig. 9).


ZEISS SmartLife Young Single Vision lenses come standard with sunglass-level™ UV protection based on UVProtect technology by ZEISS. Add ZEISS BlueGuard material to block up to 40 percent of blue light outdoors and indoors. ZEISS SmartLife Young Single Vision lenses are also available in photochromic lenses with ZEISS PhotoFusion® X to avoid annoying glare from the sun when being active outdoors. All ZEISS SmartLife Young Single Vision lenses are available with all ZEISS DuraVision® coatings for anti-reflection.

ZEISS SmartLife Young Single Vision lenses use advanced freeform technology to optimize vision for younger age groups (6 to 19 years) with active, digital and educational lifestyles. A child's age-related anatomical requirements (like the position of wear, frame parameters and lens design parameters optimize for the best visual performance for the young wearer's daily activities. ZEISS SmartLife Young Single Vision lenses provide up to 60 percent wider fields of clear view compared to conventional ZEISS Single Vision lenses.1 ZEISS SmartLife Young Single Vision lenses provide complete UV protection of the eyes and surrounding skin against harmful UV radiation outdoors, and ZEISS BlueGuard® material can be added if blue light protection is desired and recommended by the eyecare professional. Based on extensive scientific research, ZEISS SmartLife Young Single Vision lenses are designed for young eyes based on age and their connected , on-the-move lifestyle. ZEISS uses these findings and adapted state-of-the-art 3D object-space models to enhance vision for young eyes with SmartLife Young Single Vision Lenses. With ZEISS SmartLife Young Single Vision lenses, we can fit young eyes in lenses optimized for the best vision based on their age-dependent physical differences and the effects of digital screen use on their evolving vision requirements.