Mapping Vision: Measuring Real Lens Usage with Eye-Tracking
- Why real-world lens usage matters in optical design
- How the study was conducted: A novel eye-tracking approach
- Participants and lenses tested
- Visual task and eye-tracking setup
- Key findings: How different factors influence lens usage
- 1. Higher addition power results in lower zone usage
- 2. Screen type affects lens utilization
- 3. Single-vision and progressive lenses yield different usage patterns
- Implications for optical labs and ECPs
- A new era in lens optimization
- Download the Full Poster
Mapping Vision: Measuring Real Lens Usage with Eye-Tracking
Progressive power lenses (PPLs) are designed to provide seamless vision at multiple distances, making them a popular solution for presbyopia. However, until now, the exact zones of the lens that wearers actually use in real-world settings have remained unclear. Traditional optical models rely on theoretical assumptions about how wearers should use the lenses—but do those assumptions hold up in everyday tasks?
A recent study has taken a groundbreaking approach to answering this question. Using wearable eye-tracking (ET) technology, researchers have mapped precisely which regions of PPLs and single-vision (SV) lenses wearers actually look through during common visual tasks. These insights can help optical labs refine lens designs and give eye care professionals (ECPs) a better understanding of how patients truly interact with their eyewear.
Figure 1. Example of heatmaps on isolines map of the lens of two subjects with different prescribed addition while performing the same task.
Why real-world lens usage matters in optical design
Progressive lenses are engineered with an optical corridor that provides smooth transitions between near, intermediate, and far vision. However, wearers may not always use these zones exactly as intended. Several factors can influence which part of the lens a wearer actually looks through, including:
- Prescription strength & addition power – Higher addition powers may push wearers to use lower regions of the lens.
- Screen distance & ergonomics – Viewing a computer screen vs. a TV screen can shift how wearers engage with their lenses.
- Lens design & adaptation – Individual wearers may develop usage patterns that differ from the intended optical path.
Understanding these usage patterns is critical for labs and ECPs. With real-world data, lens designs can be fine-tuned to better align with how people naturally use them, leading to improved comfort, faster adaptation, and superior optical performance.
Learn more: How Manufacturing Errors in Progressive Lenses Impact Wearer Satisfaction
How the study was conducted: A novel eye-tracking approach
To explore real-world lens usage, researchers used Tobii Pro Glasses 3 eye-tracking technology to record pupil position and fixation patterns, mapping them onto the back surface of the lens. This allowed precise measurement of the vertical region-of-use—the exact portion of the lens through which participants were looking.
Participants and lenses tested
The study examined three groups of participants:
- G1 (Non-presbyopic individuals) - no need for progressive lenses.
- G2 (Presbyopic individuals with low addition power ≤2D) - moderate lens adaption needs.
- G3 (Presbyopic individuals with high addition power >2D) - stronger lens adaption needs.
Each participant tested both progressive power lenses (PPL) and single-vision (SV) lenses under controlled conditions.
Figure 2. Tobii Pro Glasses 3 with adaptation (left) and anexample of presented image (right).
Visual task and eye-tracking setup
Participants were asked to complete 20 trials in which they searched for a specific location on a digital map displayed on a screen. The study analyzed two screen conditions:
- A large TV screen (70 cm distance, 32.8° x 53.2° visual field)
- A computer monitor (65 cm distance, 15.3° x 27° visual field)
By analyzing the vertical distance (VD) from fixation points to the fitting cross, researchers determined which portion of the lens was used for each task.
Learn more: Gaze Patterns and Visual Acuity: Evaluating Progressive Lens Design with Eye-Tracking
Key findings: How different factors influence lens usage
Figure 3. The table shows the average vertical position-of-use (VD) for each participant group when searching for a location on a TV vs. PC screen, while wearing progressive (PPL) and single-vision (SV) lenses.
1. Higher addition power results in lower zone usage
- Participants with higher prescribed addition (G3) used a significantly lower part of the lens compared to those with lower addition (G2) or no presbyopia (G1).
- This was statistically significant (p < 0.05), confirming that higher addition shifts wearer fixation downward, affecting comfort and usability.
2. Screen type affects lens utilization
- G2 participants used a lower lens zone when working on a PC compared to a TV, despite similar accommodative demands.
- G3 participants exhibited the largest shifts in lens zone usage between the two screens, likely due to ergonomic factors (e.g., head posture differences when viewing a desk-level vs. wall-mounted screen).
3. Single-vision and progressive lenses yield different usage patterns
- On a TV screen, SV lenses produced similar fixation patterns across all participant groups.
- On a computer monitor, presbyopic participants (G2 & G3) used different regions of their SV lenses compared to non-presbyopic users (G1), likely due to previous adaptation to progressive lenses.
These findings validate the use of wearable eye-tracking for studying real-world lens behavior and suggest that lens design should account for screen distance, ergonomic factors, and prescribed addition when optimizing optical performance.
Figure 4. The chart illustrates the mean VD for TV and PC screen conditions across both SV and PPL designs.
Implications for optical labs and ECPs
These findings have direct implications for both lens manufacturers and eye care professionals:
For Optical Labs
- Fine-tune progressive lens designs – Adjust power distribution based on real-world fixation patterns to improve wearer comfort.
- Optimize designs for screen use – Develop specialized lenses that accommodate different ergonomic demands for computer work vs. distance viewing.
For ECPs
- Improve patient recommendations – Educate presbyopic patients on how their add power affects lens usage and comfort.
- Address screen ergonomics – Help patients adjust their screen setup to better align with natural lens usage patterns.
Learn more: Troubleshooting Progressive Lenses
A new era in lens optimization
This study represents a major leap forward in understanding how progressive and single-vision lenses perform in everyday scenarios. By leveraging wearable eye-tracking technology, researchers have moved beyond theoretical models to directly measure how people interact with their lenses in real-world tasks.
These insights pave the way for:
- More wearer-friendly progressive lens designs
- Better adaptation strategies for presbyopic patients
- Enhanced recommendations for digital screen use
As optical technology advances, integrating real-world data into lens design will become essential. Labs and ECPs now have an opportunity to apply these findings to improve visual comfort, adaptation speed, and overall patient satisfaction.
Download the Full Poster
Discover the groundbreaking method used to map real lens usage with wearable eye-tracking technology. This poster details the study’s methodology, data analysis, and key findings, revealing how different lens designs influence the specific zones wearers look through in real-world tasks. Learn how these insights can help optimize progressive and single-vision lens performance for greater visual comfort and accuracy.
