Light sensitivity

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Apart from vision, human beings have many physiological and psychological responses to light. In rare individuals an atypical response may result in serious discomfort, disease, or injury. Some drugs have a photosensitizing effect. Properties of natural or artificial light that may abnormally affect people include:

• Timing of light (upset of normal circadian rhythms, seasonal affective disorder, sleep disorders)
• Intensity of light (photophobia, sunburn, skin cancer)
• Wavelength of light ( in lupus, urticaria )
• Rapid flickers in intensity of light may trigger or aggravate epilepsy or migraine headaches.

Other effects may include vertigo, or chronic fatigue syndrome.

In rare cases individuals with solar urticaria (allergy to sunlight) can get a rash from fluorescent lighting ^[1] or may experience disease activity in very photosensitive individuals with Systemic lupus erythematosus. Standard acrylic diffusers over the fluorescent lamps absorb nearly all the UV-B radiation and appear to protect against this.^[2]

In rare cases, fluorescent lighting can also induce depersonalization and derealization, subsequently, it can worsen depersonalization disorder symptomology.^[3] Research on these rare cases is very limited and cause and effect often cannot be duplicated.

Controlled application of artificial light can be used in a program of Light therapy to treat some disorders.

Contents 1 Ultraviolet radiation risk 2 Skin and retinal cancers 3 Migraine 4 Autism and Asperger syndrome 5 Ménière's disease and Vertigo 6 Polymorphous light eruption 7 Chronic actinic dermatitis 8 Lupus 9 Actinic Prurigo 10 Solar Urticaria 11 Phytophotodermatitis 12 Additional risk for patients undergoing photodynamic therapy 13 Chronic fatigue syndrome 14 Cataracts 15 Photophobia 16 Epilepsy 17 Dyslexia 18 See also 19 References

Ultraviolet radiation risk

Some fluorescent lamps emit ultraviolet radiation that in some circumstances can exceed safe levels. The Health Protection Agency of the United Kingdom has conducted research that concluded exposure to some compact fluorescent lamps (CFLs) for 1 hour per day at a distance of less than 30 cm can exceed safe levels. Touching the exposed bulb results in equivalent exposure to ultraviolet radiation as that of being in direct summer sunlight.^[4]

Skin and retinal cancers

Ultraviolet radiation emitted by fluorescent lighting increases an individual's exposure to carcinogenic radiation by 10 to 30 per cent per year, with an associated increased probability of contracting squamous cell carcinoma by 4 percent^[5]. Melanoma has been shown to not be affected by CFLs through normal use^[6].

The constituent blue light of CFLs can aggravate retinal diseases in susceptible people^[7], but it is unlikely to occur^[8].

Migraine

Blue light, such as that emitted by CFLs, can aggravate migraine^[9], and fluorescent lamps can cause eye-strain and headache.^[10] There is no available data on the existence of CFL-induced migraine,^[11] but there is anecdotal evidence of "problems" with blue light.^[12] The charity Migraine Action [1] says its members suffer migraines induced by CFLs^[13] and there are many anecdotal reports of such occurrences.^[14][15]

Autism and Asperger syndrome

The SCENIHR report states that "people with Autism/Aspergers syndrome have reported problems which they attributed to fluorescent lighting"^[16], and any deleterious effects on sufferers of autism or Asperger Syndrome from CFLs cannot be dismissed^[17].

Ménière's disease and Vertigo

The inner-ear condition Ménière's disease can be aggravated by flicker^[18]. Sufferers of vertigo are recommended to not use fluorescent lights.^[19]

Polymorphous light eruption

Polymorphous light eruption is a condition affecting the skin thought to be caused by an adverse reaction to ultraviolet light. Its prevalence across Europe is 10-20% of the population^[20]. Artificial light sources may provoke the condition, and CFLs have been shown to produce an eruption.^[21]

Chronic actinic dermatitis

Chronic actinic dermatitis is a condition where a subject's skin becomes inflamed due to a reaction to sunlight or artificial light. Its prevalence in Scotland is 16.5 per 100,000 population. There is evidence that CFLs worsen the condition.^[22]

Lupus

The autoimmune disease Lupus is exacerbated by CFLs.^[23]

Actinic Prurigo

There is evidence that Actinic prurigo is worsened by CFLs^[24]. This disease affects 3.3% of the general population.

Solar Urticaria

3.1% of the population suffer Solar urticaria, a skin disorder affected by ultraviolet light. Some patients are directly affected by CFLs.^[25]

Phytophotodermatitis

Phytophotodermatitis may be aggravated by the additional levels of ultraviolet light emitted by CFLs.^[26]

Additional risk for patients undergoing photodynamic therapy

Patients undergoing photodynamic therapy are at additional risk of adverse photosensitive reactions caused by CFLs.^[27]

Chronic fatigue syndrome

Self-reporting suggests that 21% of chronic fatigue syndrome patients experience sensitivity to light^[28], and there have been no studies into the association between chronic fatigue syndrome and CFLs.^[29].

Cataracts

One cause of cataracts is exposure to ultraviolet light. Provided the level of UV emission from lamps is within safe limits, and the lamp a sufficient distance away from the individual, there should be no increased risk of developing cataracts.^[30]

Photophobia

Photophobia is a symptom of excessive sensitivity to light which affects 5 to 20% of the population. No studies have been conducted into the effect of CFLs on sufferers of photophobia^[31], but there is the possibility for CFLs to affect sufferers^[32].

Epilepsy

There is evidence that flicker can cause seizures in patients with photosensitive epilepsy, but there has yet to be any evidence to date attributing seizures to compact fluorescent lamps ^[33].

Dyslexia

Self-reporting suggests fluorescent lamps aggravate dyslexia, ^[34]. Tests show that dyslexic patients are unable to detect flicker emanating from light sources.^[35]

See also

• Asthenopia (eye strain)
• Photophobia
• Phototoxicity

References