Digital eye strain (DES), also known as computer vision syndrome, is physical eye discomfort that occurs after prolonged use of digital screens. It affects up to 50% of computer users. Causes include uncorrected refractive errors, accommodative and vergence anomalies, altered blinking, intense light exposure, close working distance, and small font sizes. Management involves proper correction of refractive errors, induced exophoria, blink awareness exercises, reducing light luminance, maintaining a comfortable viewing distance of 16-30 inches, and increasing font size. While blue light from digital screens does not present a biohazard, blue light filtering lenses may help reduce symptoms slightly by filtering 10-23% of blue light exposure. Experts recommend proper posture, larger screens

1. Digital Eye Strain
Alvina Pauline D. Santiago
The Medical City Eye & Vision Institute
September 2020
FPPT.com

2. Outcomes
• Define digital eye strain (DES)
• Enumerate synonyms of DES
• Identify etiologies of DES
• State principles of management of DES
• Identify unproven management of DES
• Recognize the amount of blue light emitted from computers,
tablets, laptops, smartphones
• State effect of blue color filtering glasses on DES
• Formulate management strategies for DES

3. Digital Eye Strain
Synonyms
• Asthenopia
• Visual Fatigue
• Computer Vision Syndrome
• Video Terminal Display Syndrome
• Video Display Terminal Syndrome
Shepard AL, Wolffson JS, Digital eye strain: prevalence, measurement and amelioration. BMJ Open
Ophthalmol 2018 Apr 16;3(1):e000146.

4. Digital Eye Strain defined
• Physical eye discomfort after >2 h using
digital screens
• Sometimes defined by symptomatology
and constellation of findings, hence
syndrome
The Vision Council. 2016 Digital Eye Strain Report

5. Digital Eye Strain
• Prevalence: up to 50% of computer
users
• In children, pooled prevalence of about
20%
• Impact on learning and school
performance
Shepard AL, Wolffson JS, Digital eye strain: prevalence, measurement and amelioration. BMJ Open
Ophthalmol 2018 Apr 16;3(1):e000146.
Vilela MAP etal. Prevalence of asthenopia in children: a systematic review with meta-analysis. J Pediatr
2015; 91-320-325.

6. Symptoms of DES
Accommodative /
Binocular Vision Stress
• Headache
• Blurred vision
• Nausea & Vomiting
• Breakdown of heterotropias
and phorias
External Eye Symptoms
• Blinking
• Tearing
• Dry eyes
• Photophobia
• Itchy Eyes
Shepard AL, Wolffson JS, Digital eye strain: prevalence, measurement and amelioration. BMJ Open Ophthalmol 2018 Apr
16;3(1):e000146.

7. Accommodative anomalies
• Accommodative anomalies reduce visual comfort during near
work, computer use
– Accommodative lag
– Reduced amplitude of accommodation
– The presbyope
• Evaluate distance at which screens are used
Shepard AL, Wolffson JS, Digital eye strain: prevalence, measurement and amelioration. BMJ Open Ophthalmol 2018 Apr
16;3(1):e000146.

8. https://www.aoa.org/healthy-eyes/eye-and-vision-conditions/computer-vision-syndrome?sso=y
Figure from PSPOS Infographic

9. Vergence anomalies
• Motor disorders
– Convergence insufficiency
– Decompensated heterophorias
– Poor vergence facilities (Reduced blur points, break points)
• Patients with binocular vision problems experience greater
discomfort during prolonged use of the eyes.
Shepard AL, Wolffson JS, Digital eye strain: prevalence, measurement and amelioration. BMJ Open Ophthalmol 2018 Apr
16;3(1):e000146.

10. Digital Eye Strain
Causes
• Uncorrected refractive error
• Accommodative & Vergence
anomalies
• Altered blink
• Intense light exposure
• Close working distance
• Small font size
Solutions
• Proper correction including
presbyopia
• Induced small exophoria
• Blink awareness exercises
• Reduce light luminance
• Comfortable distance 16-30 in.
• Increase font size
Coles-Brennan et al. Management of Digital Eye Strain. Clin Exp Optom 2019; 102: 18-29

11. Digital Device Exposure
• By age 3:
– 68% of children regularly use computers
– 54% online activity
• 2016: Adults
– at least 4.75 h daily on digital media (Europe)
– At least 5 hours for 30-49 age group (US)
• 2020: Pandemic figures are definitely higher
Shepard AL, Wolffson JS, Digital eye strain: prevalence, measurement and amelioration. BMJ Open Ophthalmol 2018 Apr
16;3(1):e000146.

12. Digital device exposure
Shepard AL, Wolffson JS, Digital eye strain: prevalence, measurement and amelioration. BMJ Open
Ophthalmol 2018 Apr 16;3(1):e000146.
The Vision Council. 2016 Digital Eye Strain Report.
• Multitasking using digital devices
• use 2 or more devices simultaneously
– 87% of age 20-29 (UK)
– 70% of Americans

13. Dry Eye Disease in Children
• Longer daily duration of digital device use increased
DED in Children
• Cessation of use (4wks!) in 7-12 y improved DED
– Improved tear break up time
– Improved punctate corneal epithelial erosions
Moon JH et al. Association between video display terminal use and dry eye disease in school children. J Pediatric Ophthalmology &
Strabismus 2014; 51: 87-92.
Moon JH et al. Smartphone use is a risk factor for pediatric dry eye disease according to region and age: a case control study. BMC
Ophthalmol 2016; 16: 188

14. Blue light (400-500 nm) and DES
• Harmful to retina
– suprathreshold acute doses
– Peak damage at 440 nm
– Longer duration, less intense also
cause damage
Ham et al, Retinal sensitivity to damage from short wavelength light. Nature 1976; 260: 153-155.
Jaedane et al. Retinal damage induced by commercial light emitting diodes (LEDs) Free Radical Bio Med 2015; 84: 373-384

15. How much blue?
• ICNIRP Luminance Cut off Value 10.4 cd m2
• Incandescent lamp (14%)
• Domestic Lamps including LEDs exceed limit by
10-20% (assuming intentional viewing)
• Screens at maximum brightness (Computers,
smartphones, tablets) lower than “natural”
exposures
– Highest luminance from white screen
O’Hagan et al. Low energy light bulbs, computers, tablets and the blue light hazard. Eye 2016; 30: 230-233.
International Commission on Non Ionizing Radiation Protection. Guidelines on limit of exposure to incoherent visible and
infrared radiation. Health Phys 2013; 105: 75-96

16. Blue light and digital screens
• Low levels of blue light from digital
screens NOT a biohazard
• More blue light from low energy light
bulbs (LED lights)
O’Hagan et al. Low energy light bulbs, computers, tablets and the
blue light hazard. Eye 2016; 30: 230-233

17. O’Hagan et al. Low energy light bulbs, computers, tablets and the blue light hazard. Eye 2016; 30: 230-233.
International Commission on Non Ionizing Radiation Protection. Guidelines on limit of exposure to incoherent visible and
infrared radiation. Health Phys 2013; 105: 75-96

18. O’Hagan et al. Low energy light bulbs, computers, tablets and the blue light hazard. Eye 2016; 30: 230-233.
International Commission on Non Ionizing Radiation Protection. Guidelines on limit of exposure to incoherent visible and
infrared radiation. Health Phys 2013; 105: 75-96
None of the computer monitors,
laptops, tablets, and smartphone
screens exceeded 0.39% of ICNIRP blue
light exposure limit
Blue light from these screens DO NOT
present a biohazard even with
prolonged viewing

19. Performance of Blue Blocking Lenses
• Commercially available blue light filtering
spectacles reduced calculated
phototoxicity only by 10.6-23.6%
– Blue Control (Hoya), BlueProtect (Zeiss), Crizal
Prevencia (Essilor), StressFree and Noflex
(Swisslens)
• Reduced scotopic sensitivity 2.4-9.6%
• Melatonin suppression by 5.8-15.0%
Leung TW et al. Blue light filtering spectacle lens: optical and clinical performances. PLoS One 2017; 12:
e0169114

20. Performance of Blue Blocking Lenses
Leung TW et al. Blue light filtering spectacle lens: optical and clinical performances. PLoS One 2017; 12:
e0169114

21. Blue light and DES
• Need for high quality
research (RCTs) for blue
blocking spectacles and its
effects on eye health

23. What experts recommend

25. Digital Eye Strain
• Neck & shoulder pain
• Poor posture
https://www.aoa.org/healthy-eyes/eye-and-vision-conditions/computer-vision-syndrome?sso=y

26. Proper Posture
https://www.aoa.org/healthy-eyes/eye-and-vision-conditions/computer-vision-syndrome?sso=y

27. Digital Eye Strain
• Bigger screens
– TV > desktops > laptops > mobiles
• Spreadsheets compromise
Figure from PSPOS Infographic

28. Distancing
• Improper viewing distance
18-24 in
https://encrypted-tbn0.gstatic.com/

29. Digital Eye Strain
• Improper lighting
• Glare from digital screen
Figure from PSPOS Infographic

30. Blinking
• Squinting to see better increased
blink rates if conditions can be
improved by squint
– Pinhole effect for refractive errors
– Reduce glare
• If squinting will not cause an
improvement, (small font size, low
contrast), patient squints more and
with reduced blink rates
Patel et al. Effect of visual display unit use on blink rate and tear stability. Optom Vis Sci 1991; 68: 888-92.
Freudenthaler N et al. Characteristics of spontaneous eyeblink activity during video display terminal use in healthy volunteers.
Graefes Arch Clin Exp Ophthalmol 2003; 241: 914-920
Sheedy et al. What are the visual benefits of eyelid squinting? Optom Vis Sci 2003; 80: 740-44.
• Reduced blink rates observed with
computer use
– Patel: 18.4 to 3.6 blinks
– Nakamori: 22 to 7 blinks
• Increased cognitive demand
exacerbates visual stressors, like
refractive errors and low contrast

32. Outcomes
ü Define digital eye strain (DES)
ü Identify synonyms of DES
ü Identify etiologies of DES
ü State principles of management of DES
ü Identify unproven management of DES
ü State effect of blue color filtered glasses on DES
ü Recommend management of DES

33. The computer was born
to solve problems that
did not exist before.”
— Bill Gates
The computer created
problems that did not
exist before.
-Pauline Santiago

34. References
1. Coles-Brennan et al. Management of Digital Eye Strain. Clin Exp Optom 2019; 102: 18-29
2. Computer vision syndrome. https://www.aoa.org/healthy-eyes/eye-and-vision-conditions/computer-vision-syndrome?sso=y
3. Freudenthaler N et al. Characteristics of spontaneous eyeblink activity during video display terminal use in healthy
volunteers. Graefes Arch Clin Exp Ophthalmol 2003; 241: 914-920
4. Leung et al. Filtering spectacle lenses: Optical and Clinical Performances. PLoS One 2017; 12: e0169114.
5. Moon JH et al. Association between video display terminal use and dry eye disease in school children. J Pediatric
Ophthalmology & Strabismus 2014; 51: 87-92.
6. Moon JH et al. Smartphone use is a risk factor for pediatric dry eye disease according to region and age: a case control study.
BMC Ophthalmol 2016; 16: 188
7. O’Hagan et al. Low energy light bulbs, computers, tablets and the blue light hazard. Eye 2016; 30: 230-233.
8. Patel et al. Effect of visual display unit use on blink rate and tear stability. Optom Vis Sci 1991; 68: 888-92.
9. Sheedy et al. What are the visual benefits of eyelid squinting? Optom Vis Sci 2003; 80: 740-44.
10. Shepard AL, Wolffson JS, Digital eye strain: prevalence, measurement and amelioration. BMJ Open Ophthalmol 2018 Apr
16;3(1):e000146.
11. Vilela MAP etal. Prevalence of asthenopia in children: a systematic review with meta-analysis. J Pediatr 2015; 91-320-325.
12. The Vision Council. 2016 Digital Eye Strain Report. https://visionimpactinstitute.org/wp-
content/uploads/2016/03/2016EyeStrain_Report_WEB.pdf