Digital life, although has made our life convenient and easy, it has its own side effects and detrimental health effects. In this presentation we shall go through all the effects of digital life and measures to reduce its effect
8. Source: nweyedesign.com
Medicine.net
WHAT IS TEAR FILM?
Tear film is the
liquid layer
which consists of
lipids, water, and
mucin that coats
the outer surface
of the eye,
lubricating it.
9. Source:Rolando M, Zierhut M. The ocular surface and tear film and their dysfunction in dry eye dise
Ophthalmol. 2001;45(suppl 2):S203-S210.
Stern ME, Beuerman RW, Pflugfelder SP. The normal tear film and ocular surface. In: Pflugfelder S
● A healthy tear film is important for optimal
vision and protection of surface tissues of eyes.
● Functions of tear film -
◦ Provides 80% of refractive power along with anterior
surface of cornea for focusing
◦ Lipid layer provides lubrication which gives comfort
◦ Mucin layer reduces the shear force related to blink
cycle
◦ Protects from insults
◦ Provides nourishment to cornea
IMPORTANCE OF TEAR FILM
● A healthy tear film is important for optimal
vision and protection of surface tissues of eyes.
10. FUNCTIONS OF TEAR FILM
● Functions of tear film -
◦ Main focusing part
◦ Lubrication
◦ Prevents friction while blinking
◦ Protects from desiccation
◦ Antimicrobial properties
◦ Nourishment of cornea
12. Blink Mechanism
BLINK
• The aqueous layer and the oil layer become thinner between blinks.
• The blink restores these layers.
BLINK
• The blink restores these layers.
• The aqueous layer and the oil layer become thinner between blinks.
Blink Mechanism
13. What is Computer Vision Syndrome?
(CVS)
◦ It is also known as Digital Eye Strain
◦ It occurs due to constantly focusing the eyes on a
computer or other screens for long periods of time
resulting in inability of eye muscles to recover from
the strain.
◦ It results in chronic dry eye
Source: Surv Ophthalmol 50:253–262, 2005.
15. Source: Surv Ophthalmol 50:253–262, 2005.
Why Does CVS Occur?
o Computer screens are made up of pixels or tiny dots,
which is hard for eyes to focus. The computer user
must therefore focus again and again to keep the
images sharp. This results in receptive stress of the
eye muscles.
o Dry eyes occur due to lower blinking rate of users.
16. Source: Surv Ophthalmol 50:253–262, 2005.
CVS just doesn’t occur through use of
computers
CVS just doesn’t occur through use of
computers
• Laptop
• Television
• Smartphone
• Tablets
• Any other visual aid
22. Source: American Optometric
Association
◦ Dry eye is a condition where there is excessive evaporation of tears or the
eye does not produce enough quality tears to lubricate and nourish the
eyes properly
◦ Quality as well as quantity of tears are affected
WHAT IS DRY EYE?
Inadequate
amount of
tears
Poor quality
tears
(evaporation)
23. 14
Lacrimal gland
In an Aqueous-deficient dry eye, the lacrimal gland is poorly
functioning
Not enough tears Thin aqueous layer Dry cornea Dry Eye Symptoms
24. 14
Evaporative dry eye, the Meibomian Glands are
Dysfunctional (MGD)
Unstable lipid layer
Dry cornea Dry Eye Symptoms
Too much evaporation
Thin aqueous layer
Poor function of
meibomian glands
26. ● AGE
• Dry eyes are experienced by majority of people over
65 years
● GENDER
• Women have more chances of having dry eyes due
to hormonal changes which can be due to
pregnancy, the use of oral contraceptives and
menopause
● MEDICATIONS
• Medicines such as antihistamines, blood pressure
medications, decongestants and antidepressants
can decrease tear production
WHAT CAUSES DRY EYES?
Source: American Optometric
Association
AGE
Dry eyes are experienced by majority of people
over 65 years
GENDER
Women have more chances of having dry eyes due to
hormonal changes which can be due to pregnancy, the use
of oral contraceptives and menopause
MEDICATIONS
Medicines such as antihistamines, blood pressure
medications, decongestants and antidepressants can
decrease tear production
27. CAUSES…cont..
MEDICAL CONDITIONS
• People suffering from diabetes, thyroid problems and
rheumatoid arthritis are more prone to have dry eyes
ENVIORNMENTAL CONDITIONS
• Conditions such as windy and dry climates, exposure
to spoke can increase in tear evaporation which
increases the risk of dry eye.
OTHER FACTORS
• Staring at gadget screens for long time resulting in less
blinking
• Use of contact lenses
Source: American Optometric
Association
MEDICAL CONDITIONS
• People suffering from diabetes, thyroid problems and rheumatoi
arthritis are more prone to have dry eyes
ENVIORNMENTAL CONDITIONS
Conditions such as windy and dry climates, exposure to smoke
can increase in tear evaporation which increases the risk of
dry eye.
OTHER FACTORS
• Staring at gadget screens for long time resulting in less blinking
• Use of contact lenses
34. Low humidity
chilled
environments,
cause
evaporation from
the aqueous
layer
Daily exposure
to dry air can
cause
uncomfortable
situation to
progress to a
chronic change
in the tear film
Exacerbation of
dry eye
symptoms
Air condition in
cars also cause
tear evaporation
Why Air Conditioning doubles the risk
of dry eye?
Source: Ocular Surgery News Europe/Asia-Pacific Edition (Archive), February 200
35. Frequent Air Travel Exacerbates
Dry Eye Symptoms..!!!
• Average humidity in aircraft cabin: 9-28% @ 23
to 24° C which is relatively low
• It increases tear evaporation
• Symptoms have direct correlation with the
duration of flight
• Occurs in many people who otherwise do not
have dry eye complaints or problems
Source: Ocular Surgery News Europe/Asia-Pacific Edition (Archive), February 20
36. Why you should not ignore
Dry Eye Symptoms?
• Eye infections. Your tears protect the surface of
your eyes from infection. Without adequate
tears, you may have an increased risk of eye
infection.
• Damage to the surface of your eyes. If left
untreated, severe dry eyes may lead to eye
inflammation, abrasion of the corneal surface,
corneal ulcer and vision problems.
• Decreased quality of life. Dry eyes can make it
difficult to perform everyday activities, such as
reading. Source: Ocular Surgery News Europe/Asia-Pacific Edition (Archive), February 20
37. Ten Steps to get
relief from
Computer Eye Strain
38. Ten Steps to get
relief from
Computer Eye Strain
39. o Computer users should have an eye exam before
they start working on a computer and once a year
there after (NIOSH).
o During your exam, following things are noted:
● Presence of Dry eyes
● Refractive errors
1. Get a comprehensive eye exam
Ref: http://www.allaboutvision.com/cvs/irritated.htm
NIOSH: National Institute of Occupational Safety and Heal
40. Ref: http://www.allaboutvision.com/cvs/irritated.htm
2. Use proper light
◦ Bright lights, windows and overhead lights contribute
to discomfort glare – adjust these to avoid any glare
◦ Adjust ambient light – not too bright- not too dull
41. Ref:
http://www.allaboutvision.com/cvs/irritated.htm
accessed on 15-02-2016
3. Minimize Glare
◦ Glare on walls and finished surfaces, as well as
reflections on your computer screen also can cause
computer eye strain
◦ Consider installing an anti-glare screen on your
monitor
◦ If you wear glasses, purchase lenses with anti-
reflective (AR) coating
42. 4. Upgrade your display
◦ LCD screens are better than old tube style monitors
◦ Choose screen with highest resolution possible
◦ Choose a relatively larger display
◦ Select a display that has a diagonal screen size of at
least 17 -19 inches (desktop computers)
Ref: http://www.allaboutvision.com/cvs/irritated.htm
43. 5. Adjust your computer display settings
● Keep the brightness same as of your
surrounding workstation
● Text size and contrast:
Ref: http://www.allaboutvision.com/cvs/irritated.htm
44. Normal blink rate -14 times
/minute.
During computer use - 4 to 6
times per/minute
Source: Surv Ophthalmol 50:253–262, 2005.
45. 6. Blink more often
Blinking is very important as it
moistens your eyes which prevents
dryness and irritation.
Every 20 minutes, blink 10 times by
closing your eyes as if falling asleep
(very slowly). This will help rewet
your eyes Ref: http://www.allaboutvision.com/cvs/irritated.htm
BLINK
46. 7. Exercise your eyes
Constant focus on
screens- eye results in
strain/tiring/fatigue
Look away from your
computer at least every 20
minutes and gaze at a distant
object (at least 20 feet away)
for at least 20 seconds (20-
20-20 rule)
Another exercise is to look far away
at an object for 10-15 seconds, then
gaze at something up close for 10-
15 seconds. Then look back at the
distant object. Do this 10 times
(prevents accommodation spasm)
Don’t forget to blink
during the exercise
Ref: http://www.allaboutvision.com/cvs/irritated.htm
48. 8. Take frequent breaks
Two 15 min breaks
Additional 4 mini breaks
of 5 min recommended
by NIOSH
By doing so, work output
indeed maintained or
increased
During your computer breaks,
stand up, move about and
stretch your arms, legs, back,
neck and shoulders to reduce
tension and muscle fatigue
Ref: http://www.allaboutvision.com/cvs/irritated.htm
51. 10. Consider computer eyewear
Check for any
refractive error
This is especially true if
you normally wear contact
lenses, which may become
dry and uncomfortable
during sustained computer
work
Computer glasses
also are a good
choice if you
wear bifocals or
progressive
lenses
Source: http://www.allaboutvision.com/cvs/irritated.htm
53. Blue Light
◦ Any source of light gives of blue light – sun, torch,
bulb, mobiles, gadgets.
◦ We get plenty of blue light each day from sun, but
after sunset we are exposed to it from artificial light
sources
Ref: http://www.allaboutvision.com/cvs/irritated.htm
54. Blue Light
◦ Before advent of artificial light, the sun regulated our
sleep schedule. But today we are exposed to light all
day and night
◦ Dark environment signals our body to start producing
melatonin, responsible for making us fall asleep
◦ Exposure to blue light inhibits melatonin production
and disrupts circadian rhythm
◦ Compared to fluorescent & incandescent bulb, LEDs
can emit significant blue light
55. Blue Light Blocking Glasses
◦ Does blue light cause damage to the Eye –
◦ The evidence is conflicting and there is no clear cut
role yet established in disease causation – ARMD.
◦ As natural lens ages, it gets deposited with yellow
chromophores which block UV lights and blue light
◦ So still there is no clear evidence.
◦ There is enough evidence that blue light blocks
melatonin secretion, so if you use screen long after
sunset, these glasses might help stop you from
staying up late.
56.
57. Tips to stimulate Tear Production
Source: http://www.allaboutvision.com/cvs/irritated.htm
Images: Google search
Drink plenty of water
Include sources of fatty acids in diet
(flaxseed, fish oil, almonds)
Eat fruits and vegetables rich
in vitamin A and E
Avoid eating too much of meat,
fats and carbohydrates
58. Artificial Tears
● Computer Vision Syndrome is one of the major
reasons for dry eye.
● Dry eyes occurs due to excessive evaporation/
reduced blink rate.
● Consult your medical professional as this can be
easily managed by lubricating drops
59. When to Contact a Medical
Professional
• Red or painful eyes
• Flaking, discharge, or a lesion on eye or eyelid
• Previous trauma to eye or Bulging eye
• Joint pain, swelling, or stiffness
• Dry mouth
• Dry eyes not responding to self-care measures within few days
Source: http://www.allaboutvision.com/cvs/irritated.htm
Images: Google search
60. SUMMARY
● When enough quality tears are not produced by the
eyes, there is occurrence of dry eye.
● Due to this, the lubrication and nourishment to the
eye is insufficient.
● Computer Vision Syndrome is one of the major
reasons for dry eye.
● To avoid dry eye, efforts should be made to use
tips which stimulate tear production.
● In case of severe problem, contact a medical
professional.
62. Don’t forget to blink..!!
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Notes de l'éditeur
A healthy tear film is essential for optimal vision and protection of ocular surface tissues. Key functions of the tear film are to provide:
Optical clarity and refractive power:
The tear film and anterior surface of the cornea provide about 80% of refractive power for the focusing mechanism (Rolando and Zierhut, 2001).
Tear film breakup can degrade visual acuity, especially contrast sensitivity.
Lubrication and comfort:
Lipid layer provides lubrication, promoting comfort.
Mucin layer decreases the shear force associated with the blink cycle.
Protection from insults:
Lipid layer protects the mucosal ocular surface against desiccating environments.
Antibacterial proteins include lysozyme, lactoferrin, and peroxidase.
A nourishing environment for corneal epithelial cells, since the corneal epithelium lacks vasculature:
Electrolytes maintain pH.
Growth factors promote epithelial cell growth and wound healing.
Antioxidants to help maintain a reducing environment.
References
Rolando M, Zierhut M. The ocular surface and tear film and their dysfunction in dry eye disease. Surv
Ophthalmol. 2001;45(suppl 2):S203-S210.
Stern ME, Beuerman RW, Pflugfelder SP. The normal tear film and ocular surface. In: Pflugfelder SP,
Beuerman RW, Stern ME, eds. Dry Eye and Ocular Surface Disorders. New York, NY: Marcel Dekker;
2004:41-62.
Failure to blink regularly, such as when staring at a computer screen for long periods of time, can also contribute to drying of the eyes.
Redness, Pain, Fatigue, Decreased tolerance to screen time
When working at a computer, people blink less frequently — about one-third as often as they normally do — and many blinks performed during computer work are only partial lid closures, according to studies.
Tears coating the eye evaporate more rapidly during long non-blinking phases and this can cause dry eyes. Also, the air in many office environments is dry, which can increase how quickly your tears evaporate, placing you at greater risk for dry eye problems.