Side effects of bright light

1. Side effects of bright light
Prepared by:
Omnia Abdelmenem Mohamed
Nourhan khalaf Mansour
Yosra amr bastwisy
Rania Mahmoud asaad
Noha mohamed abdelrehim
Nahla abdelhamid ali

2. Which light is the harmful light ?
 Direct looking at the sun light
 Blue light
 In door light
 Lasers

3. Sun light
 Sunlight is the main source of UV radiation
 Exposure to UV rays raises the risk of eye cancers, cataracts, growths on the
eye and sunburn on the eye.

4.  Even though the sun is 93 million miles away, it can still cause serious and irreversible damage.
 Exposure to ultraviolet radiation will cause harmful effects which may be acute (short lived and reversible) Or
chronic that may be life threatening and include immune suppression, eye damage. The from eyes can absorb
more than 99% of ultraviolet radiation So cataract, corneal and macular damage all are possible chronic effects
from UV radiation and this can lead to blindness, melanoma ( skin cancer ) may develop within the eye causing
intraocular melanoma and it is common malignancy in the eye in whites.
 Over exposure to both artificial and natural UV radiation is a public health concern.
 Many years ago, there was a common belief that blindness and solar retinitis were caused from the sun’s ray to
the retina due to thermal injuries.
 Damage type depends on specific parameters such as : power level , exposure time, wavelength and anatomy of
the eyebrow and eyelids.
Why parents tell their children not to look direct to the sun?

5.  The human eye and ocular tissue is sensitive organ to light even
ultraviolet, visible and infrared rays are more vulnerable to damage
than the skin.
 There are three critical ocular structure may be affected by
ultraviolet spectrum: the cornea, the lens and the retina
 The eye has a protection mechanism against excessive exposure to
light
 Dual mechanism of indirect heat from the iris acting on the lens
through heat transfer from its vascular neighboring structure and
direct exposure of infrared to the lens only couldn’t produce lens
opacities.

6. How to select my sunglasses
 Make sure they provide 100 percent UV protection from all UV light
 Avoid blue colored lens , Lenses that block all blue light are usually amber
colored and make your surroundings look yellow or orange
 Sunglasses should have the largest lenses possible to protect your eyes
from sun damage.

7.  The cornea is exposed to man-made and natural light except when sleeping, level of solar ultraviolet
irradiance that reaching the eye could exceed the damage threshold.
 Over exposure may lead to acute effects like inflammation of the cornea (photo keratitis) which is caused
by ultraviolet B and Non solar ultraviolet C.
 It is more prevalent in individual participates in activities in environment such as :beach activities- water
sports and snow skiing.
Corneal damage

8. 7. Conjunctival chemosis
8. Anterior uveitis and aqueous flare
9. Pain
10. Foreign body sensation
11. Photophobia
12. Lacrimation and blepharospasm
Signs and symptoms
1. Conjunctival and circumlimbal infection
2. Epithelial granulation
3. Irregular corneal reflex
4. Corneal edema
5. Bilateral punctate keratitis
6. Pupillary miosis
 It has been reported that cornea absorbs 100% of ultraviolet C (100-200 nm ) and 90% of ultraviolet B (280 -315 nm )
and 60% of ultraviolet A (315-400 nm ) and blue light spectrum of the visible spectrum affect the eye (380-500 nm ).
 It’s estimated that 200 seconds of un-attenuated exposure to solar, Ultraviolet B within the 295 to 315 nm wavelength
may result in keratitis

9.  The inner most layer of the eye ball.
 Visual perception occur when radiation with wavelength between 400-760 nm reaches the retina.
 Two classes of photochemical retinal damage have been recognized.
 class one: characterized by the rhodopsin action.
 class two: damage confined to the retinal pigment epithelium.
 Direct exposure of the sunlight to retina may destroy their ability to respond to visual stimulus.
 Photo thermal and photo coagulation will destroy the rods and cones creating small blind area within the victim
knowledge.
 It may be temporary or permanent.
 Protection mechanism begin to decrease around the age of 40.
Retinal damage

10.  It’s a retinal damage that occur due to solar radiation
 Causes :
 Not always due to sun exposure but it may be due to retinal damage
1. Excessive exposure to solar radiation.
2. History of sun exposure.
3. Solar eclipse viewing without proper precautions.
4. Drug intoxication.
5. Sun bathing.
 Signs and symptoms:
• It may be bilateral but can affect also one eye.
• Normal or macular edema that can develop small yellowish which spot with
surrounding grey , granular pigmentation in central foveae
Solar retinopathy

11. Safe viewing of transit of Venus
 For a safe viewing we should wear a special sunglasses that transmit 0% of harmful UV radiation
 Filters used is made from black polymer sheets , mylar sheets and also we can use the welders glass

12. Unsafe viewing
 Viewing solar without the special glasses
 Using films , smoked glass , sunglasses , black and white films ,
photographic negatives films and polarizing filters
 Most of these filters transmit high level of harmful radiation
causing retinal burn

13. Safety for transit of venus
 Never look at sun without proper eye protection
 Don’t use any smoked glasses or films
 Don’t look at sun refelection

14. How can indoor light harm?
 Exposure to harsh fluorescent lighting can cause eye strain and blurred
vision
 Warm colored spectrum like red and green is better for eye than cool colors
like blue
 Warm color is also more safer and comfortable for eye during reading and
study

15. Blue light :
Permanent retina scarring
temporary retina scarring
 IR light :
Eye cataract due to hat of the lens
 UV light :
Long term exposure produce cataract
 fluorescent lighting :
eye strain and blurred vision

16. Blue light
It’s the most dangerous light as it may cause temporarily or permanent blindness

17. Where Are You Exposed to Blue Light?
 Sun light is the largest source of blue light
 Fluorescent light
 CFL (compact fluorescent light) bulbs
 LED light
 Flat screen LED televisions
 Computer monitors, smart phones, and tablet screens
Blue light and your eye

19. Welders’ eye
Definition :
 Exposure to ultraviolet rays from the electrical arc that wielding machines emit
causing a condition called welder’s eye
 Patient may feel the pain immediately or After several of hours
 It’s effect is similar to sunburn on skin
 It produces injury to the mucous membrane

20. Effect:
It may cause headache and much more severe eye conditions like
• Flash burns
• Ultraviolet (UV) burn.
• Photokeratitis
• Welder’s Flash
• Welder’s Eye
• Snow Blindness

21. Factors this effects depends on :
 The angle of radiation that enters the eye
 Type of protection used during welding
 The distance between the arc and the eye
 Radiation intensity

22. Symptoms
 Eye pain (Unable to open eyes)
• Gritty feeling
• Watering of eyes
• Blurry vision
• Mild to severe Headache
 Weeping of tear duct
 Sand sensation in eye(Feeling of having dirt in the eye)
 inability to look at light sources (photophobia)
 reddening of the eye and membranes around the eye (bloodshot)

23. Etiology :
 Welding arcs give off radiation over a broad range of wavelengths
 UV radiation, visible light, and IR radiation can reach the retina and cause
several damages
 The light from welding process is so rapid

24. How to prevent welder’s flash
 wear a protective welding helmet
 Using filter glasses in the helmet
 wear proper protective eyewear, glasses or face shields
(safety goggles)
 Avoid looking to the bright light

25. Skin hazards associated with welding and radiation?
 UV radiation in a welding arc will burn unprotected skin
 Infrared radiation and visible light normally have very little effect on the skin.
 skin cancer May accrue due to long term exposure

26. Light therapy
 In light treatment, also known as phototherapy, you sit a few feet away from a particular light box in order to be
exposed to bright light within the first hour after waking up each day. Light therapy imitates natural outside light and
appears to alter mood-related brain chemicals.
 One of the first-line treatments for fall-onset SAD is light therapy. It typically begins to work within a few days
to a few weeks and has few adverse effects. There is limited research on light treatment, but it appears to be useful
for the majority of SAD sufferers.
 Before purchasing a light box, discuss your needs with your health care practitioner and acquaint yourself with
the various features and options so that you get a safe and effective product. Also inquire about when and how to
utilize the light box.

27. Psychotherapy, also called talk therapy, is another option to treat SAD.
A type of psychotherapy known as cognitive behavioral therapy can help you:
 Learn good coping mechanisms for SAD, including limiting avoidance behaviour and planning
meaningful activities.
 Identify and modify any negative ideas and habits that may be contributing to your poor mood.
 Learn how to manage stress
 Build in healthy behaviors, such as increasing physical activity and improving your sleep patterns
Psychotherapy

28. SAD ( seasonal affective disorder)
 Seasonal affective disorder is a type of depression associated with seasonal changes; SAD begins and finishes around
the same time each year. If you're like the majority of people with SAD, your symptoms will begin in the fall and
continue into the winter, leaving you exhausted and depressed. Typically, these symptoms resolve during the spring and
summer. Less frequently, SAD induces depression in the spring or early summer, which resolves in the fall and winter.
 Light therapy (phototherapy), psychotherapy, and medication may be used to treat SAD.

29. Diagnosis
Even with a thorough evaluation, seasonal affective disorder can be difficult to diagnose because other types of
depression and other mental health conditions can cause similar symptoms.
To help diagnose SAD, a thorough evaluation generally includes:
 Physical exam. Your physician may do a physical examination and ask you in-depth questions about
your health. In some circumstances, depression may be associated with a physical health issue.
 Lab tests. For instance, your doctor may perform a blood test called a complete blood count (CBC) or
examine your thyroid to ensure that it is functioning properly.
 Psychological evaluation. Your health care provider or mental health professional will inquire about
your symptoms, thoughts, feelings, and behaviour patterns in order to identify signs of depression. You
can complete a questionnaire to assist in answering these questions.

30. Fall and winter SAD
Symptoms specific to the onset of winter SAD, also known as winter depression, may include
the following.:
 Oversleeping
 Appetite changes, especially a craving for foods high in carbohydrates
 Weight gaining.
 Tiredness or low energy.
Spring and summer SAD
Symptoms specific to summer-onset seasonal affective disorder, sometimes called summer
depression, may include:
 Trouble sleeping (insomnia)
 Poor appetite
 Weight loss
 Agitation or anxiety
 Increased irritability

31.  In the majority of instances, seasonal affective disorder symptoms manifest in late autumn or early
winter and vanish throughout the brighter months of spring and summer. Less frequently, those with
the reverse pattern have onset of symptoms in the spring or summer. In any scenario, the severity of
the symptoms
 Signs and symptoms of SAD may include:
• Feeling listless, sad, or depressed for the majority of the day, nearly every day.
• Losing interest in activities that were once enjoyable.
• Having low energy and feeling sluggish.
• Having trouble sleeping too much.
• Experiencing carbohydrate cravings, overeating, and weight gain.
• Having trouble concentrating.
• Feeling sad, useless, or guilty.
• Having suicidal thoughts.

32. Seasonal changes and bipolar disorder
Bipolar disorder increases the likelihood of developing seasonal affective disorder. Some
individuals with bipolar disorder may experience manic episodes during a particular season.
Spring and summer, for instance, might trigger symptoms of mania or a less severe type of mania
(hypomania), as well as worry, restlessness, and impatience. Additionally, they may experience
depression during the fall and winter.

33. Causes
The specific cause of seasonal affective disorder remains unknown. Some factors that may come into play
include:
 Your biological clock (circadian rhythm).
 Reduced levels of sunlight in autumn and winter may contribute to the onset of winter-onset SAD.
 This decrease in sunshine may upset the body's biological rhythm and cause depressive feelings.
 Serotonin levels.
 Serotonin, a neurotransmitter that affects mood, may play a role in seasonal affective disorder (SAD).
 Reduced exposure to sunlight can lead to a decline in serotonin, which can trigger depression.
 Melatonin levels.
 Seasonal changes can disturb the equilibrium of the body's SAD appears to be more common among people who live far
north or south of the melatonin level, which influences sleep patterns and mood.

34. Medications
• Some individuals with SAD may benefit from antidepressant medication, particularly if
their symptoms are severe.
• People with a history of SAD may benefit from an extended-release formulation of the
antidepressant bupropion (Wellbutrin XL, Aplenzin) for the prevention of depressive
episodes. Additional antidepressants may also be used to treat SAD.
• Your health care practitioner may consider beginning antidepressant treatment prior to the
annual onset of your symptoms. In addition, he or she may recommend that you continue
taking the antidepressant beyond the time when your symptoms would ordinarily subside.
• Remember that it may take many weeks before you experience the full advantages of an
antidepressant. In addition, you may need to test multiple drugs before finding one that
works well and has minimal adverse effects.

35. Risk factors
Seasonal affective disorder is diagnosed in women more frequently than males. And younger folks are more
susceptible to SAD than older adults.
Factors that may increase your risk of seasonal affective disorder include:
 Family history. People with SAD may be more likely to have relatives who suffer from SAD or another type of
depression.
 Having major depression or bipolar disorder. Symptoms of depression may worsen seasonally if you have one of
these conditions.
 Living far from the equator. This may be the result of shorter days in the winter and longer days in the summer.
 Low level of vitamin D. When the skin is exposed to sunshine, a small amount of vitamin D is created.
 Vitamin D can assist in enhancing serotonin function.
 Less sunlight and insufficient vitamin D from meals and other sources may lead to low vitamin D levels in the body.

36. Complications
Consider seriously the signs and symptoms of seasonal affective disorder. As with other forms of
depression, SAD can worsen and lead to complications if left untreated. These may consist of:
 Social withdrawal
 School or work problems
 Substance abuse
 Other mental health disorders such as anxiety or eating disorders
 Suicidal thoughts or behavior

37. Eye health concerns on dental staff and equipment
Every occupation has its own risks and benefits, and safety concerns are of paramount importance.
Protection with proper safeguard is mandatory. With the advanced knowledge about infection control and
personal protection, a lot of emphasis is required on eye protection.

38. Hazards
 Class I
These lasers cannot emit laser radiation at known hazard levels.
 Class I.A.
This is a special designation that applies only to lasers that are “not intended for viewing,” such as a supermarket laser scanner.
The upper power limit of Class I.A. is 4.0 mW.
 Class II
These are low-power visible lasers that emit above Class I levels but at a radiant power not above 1 mw . The concept is that the human
aversion reaction to bright light will protect a person.
 Class IIIA
These are intermediate power lasers (cw: 1-5mW), which are hazardous only for intra beam viewing. Most pen-like pointing lasers are
in this class.
 Class IIIB
These are moderate power lasers.
 Class IV
These are high power lasers (cw: 500 mW, pulsed: 10 J/cm2 or the diffuse reflection limit), which are hazardous to view under any
condition (directly or diffusely scattered), and are potentials fire hazard and a skin hazard. Significant controls are required of Class IV
laser facilities

39. General safety measures include:
 Environment
Laser light properties include the concept of beam collimation, with minimal divergence with distance.
Other safe operating methods include the protection of non-target tissue during laser surgery. Reflective instruments and
those with mirrored surfaces should be avoided since they can cause damage to non-target tissue.
Shielding may be used as an effective method to avoid inadvertent contact of the beam with tooth enamel or root
surfaces. A no. 7 wax spatula or the small end of a Prichard periosteal elevator can be inserted into the gingival sulcus to
serve as an effective shield when lasing soft tissue near teeth.
Appropriate power settings and time frames are essential to reduce the risks. Most laser accidents and injuries can be
prevented if appropriate control measures are recognized and implemented.

40. Safety officers
 The safety officer is appointed to ensure that all safety aspects of laser use are identified and enforced.
Ideally, this could be a suitably trained and qualified dental surgery assistant.
 Duties of the laser safety officer (LSO) include the following:
 Confirm classification of the laser.
 Read manufacturers' instructions concerning installation, use and maintenance of the laser equipment.
 Oversee controlled area and limit access.
 Post appropriate warning signs.
 Recommend appropriate personal protective equipment, such as eye wear and protective clothing.
 Assume overall control for laser use and interrupt treatment if any safety measure is infringed.
 Laser equipment should be properly assembled for use.
 Maintain a log of all laser procedures carried out, relative to each patient, the procedure and laser operating
parameters.
 Maintain an adverse effects reporting system—to record any accidents during laser use.

41.  Oversee maintenance protocols for laser equipment.
 Train workers in the safe use of lasers.
 Local rules
 The local rules should be read and signed by all practice personnel involved in the delivery of laser treatment and
updated regularly. It should include:
 Name and address of the practice.
 Each laser used, identified by manufacturer, wavelength, emission mode, power output, delivery system and serial
number
 Personnel permitted to use the laser, training and education of personnel involved in the use of lasers.
 Designation of the authority and responsibility for the evaluation and control of laser hazards to a laser safety officer.
 A written laser safety policy, to include Establishment of a quality assurance programme, including regular inspection
and maintenance of the laser equipment.
 Management of incidents and accidents, including reporting, investigation, analysis and remedial action.
 Training

42. Thank you…