Smaller screen size and closer viewing distances are expected to decrease blink rate, potentially increasing the risk of dry eye and digital eye strain.

• Since the pandemic has started, surveys have shown increased in screen time use, especially in children. This includes TVs, tablets, computers, smart phones and gaming consoles.​
• Children in U.S.A. use screen of an average of 3 hours on weekdays, and 6 hours on weekend days. ​
• 41 % of American teens report >8 h/day on screens.​
• Research shows that when looking at a screen, adults and college students tend to blink 50% less compared to doing a daily activity.​
• Reduced blinking will result in dry, red, tired and/or burning eyes. It can also cause fluctuating or blurry vision. This is known as Dry Eye Syndrome or DigitalEye Strain (Figure 1).
• Many people report using smartphones for tasks that include homework,communication, research, and productivity, but laptops/desktops are still often the primary tools for structured academic or professional work.​
• Young people hold phones much closer (\~20cm)  than traditional near-vision reading distances (\~40 cm) when using them for typical tasks like texting or web browsing, and when lying down. ​
• There are limited studies on whether blink rate in children reduces with screen use, and whether viewing habits (screen size and distance) influence its effect. ​
• In our experiment, we are measuring spontaneous blink rate (SBR), which means how many times you naturally blink in a minute without conscious effort.​

Manipulated variable: Device's size and screen distance  ​ Responding variable: Spontaneous blink rate Controlled variable: Same location, same time​, same lighting of the room​, same screen brightness​, same task​, same duration of activity​ Control: UNO online card game

Experiment 1 Computer​

• Choose subjects of the age range of 8-13 years old​
• Set up online UNO game on computer​
• Have your subjects sit in the exact same spot where there is a consistent room lightening, and no glare on screen​
• Demonstrate how to play UNO
• Measure the viewing distance (40-50cm)​
• Start the timer and have subjects complete the task for a 1 minute ​
• Count and record how many times the participant blinks​

Experiment 2 Phone​

• Choose subjects of the age range of 8-13 years old​
• Set up online UNO game on phone​
• Have your subjects sit in the exact same spot where there is a consistent room lightening, and no glare on screen​
• Measure the viewing distance (40-50cm)​
• Start the timer and have subjects complete the task for a 1 minute ​
• Count and record how many times the participant blinks

Experiment 3 Phone personal choice​

• ​Choose subjects of the age range of 8-13 years old​
• Set up online UNO game on phone​
• Have your subjects sit in the exact same spot where there is a consistent room lightening, and no glare on screen​
• Measure the viewing distance (40-50cm)​
• Start the timer and have subjects complete the task for 1 minute ​
• Count and record how many times the participant blinks​

• There's an average reduction in blink rate by 33% when using a phone at 40-50cm compared to a computer screen at the same distance​
• There's an average reduction blink rate of 28% when using a phone at 20-30cm compared to a phone at 40-50cm​
• We can extrapolate that blink rate decreases 60% when switching from laptop at40-50 cm to holding a phone close to the eyes​
• ​

• There's an average reduction in blink rate by 33% when using a phone at 40-50cm compared to a computer screen at the same distance​ (Graph 1)
• There's an average reduction blink rate of 28% when using a phone at 20-30cm compared to a phone at 40-50cm​ (Graph 2)
• We can extrapolate that blink rate decreases 60% when switching from laptop at 40-50cm to holding a phone close to the eyes​

• Research has shown that smaller screen size requires more cognitive attention ​
• Phones have smaller screen size compared to laptop, making it harder to focus and see clearly, hence requiring more cognitive attention. ​
• When you hold a screen closer to your eyes it increase the amount of accommodative (eye focusing) demand.
• When possible, students should limit amount of screen time. ​
• Even short duration has an immediate effect on blink rate and possible dry eyes. ​
• Screen distance​
• Screen size​
• Given the ubiquitous use of smartphones by children, future work shouldexamine whether effects persist over a longer term causing cumulative damage to the ocular surface.​

Effects of Dry Eye Syndrome

• Physical: Dry Eyes can cause Physical, Mental &Financial Burden (Corneal Ulcer, Contact lens intolerance, Chronic Pain Syndrome​, Blurry vision and  Blindness​)
• Mental: Poor Concentration​, Poor Grades 2-3x, Risk of Depression, Low Quality of Life​ (even worse than glaucoma, macular degeneration and retinal detachment)​
• Financial: Treatment cost to patients $750-2500/yr​, Cost to insurance $25 billion/yr, Cost to society $55 billion/yr​

How can we help others reduce the effects of Dry Eye Syndrome from Screen Use

• Use the 20-20-20 rule ​
• Blink more often when using screens ​
• Sit at a proper distance from screens ​
• Use larger screens when possible ​
• Take regular breaks

Future Experimental Considerations

• Add more subjects to the experiment​
• Measure the effect of working distance and blink rate​
• Determine if reading text on a screen vs paper will change the of spontaneous blink rate​
• Determine if viewing a static versus a moving object will change the of spontaneous blinkrate​
• Determine the difference between blink rate for a long time of period compared to a shorteramount of time ​

• Small sample size​
• Subjects got distracted while doing their tasks​
• Human counting error of blinks​
• Human variability​
• Short testing time​
• Measurement error​

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• We would like to thank our science teachers, Ms. Krause and Dr. Sumners, for their guidance, support, and valuable feedback throughout this project.​
• We would also like to thank our school West Island College for this opportunity​