fluorescent

fluorescent

 

fluorescent lamp impact on vision and health

50kHz

 

Figure 2 The voltage waveform across fluorescent lamp; horizontal axis is time, vertical axis is voltage.

PFC fluorescent lamp has only high frequency voltage across lamp. The voltage waveform is shown in Figure 2.

Although the brightness of the lamp is still proportional to the applied voltage, but the human eye cannot keep changing with such a high frequency. Light variation is so fast that eyes cannot keep up, so the pupils will not contract even under strong peak light condition. Strong light will project on the retina and retina will be hurt. Long-term high-brightness light can cause keratitis (corneal epidermal necrosis, loss), eye pain, photophobia,tearing,corneal injury,lens damage, the posterior subcapsular cortex muddy, cataract formation,Vitreous injury,retinal damage, macular retinal choroidal damage, central vision loss, fundas as same as Eclipse retinitis, or even blindness.

Research for Strong Light Impact on Eyes

Wright State University and University of Wisconsin/Oshkosh did research and found prolonged intense visible light exposure can lead to photoreceptor cell damage. Visual cell damage can then progress to cell death and loss of vision, or retinal light damage may regress with recovery of function[7].

University of Florida found epidemiologic evidence indicates a trend toward association between severity of light exposure and age-related macular degeneration that is a leading cause of blindness in the western world[8].

French doctors found: All the ocular structures, from cornea to retinal layer, can be damaged by exposure to the light radiations. Acute keratitis combined with conjunctivitis will result from an intensive photonic exposure[9].

Incandescent Lamp Brings Ultraviolet Light

The electric current (in the gas) excites mercury vapor which produces short-wave ultraviolet light that then causes a phosphor coating on the inside of the bulb to fluoresce, producing visible light. So fluorescent lamps emit ultraviolet (UV). Long term exposure to ultraviolet light may cause cataracts, macular disease, blurred vision and image distortion symptoms. Long-term UV radiation can cause skin aging black and skin cancer. Long-term repeated ultraviolet radiation can cause chronic blepharitis, conjunctivitis, conjunctival elasticity and gloss loss, and pigment hyperplasia. UV-induced electric photopthhalmia is a common eye disease. UV can cause solar ophthalmia, actinic conjunctivitis, electric ophthalmia, flash eye, arc eye, welder flash and industrial photopthhalmia, etc. All these are called the customary system electric ophthalmia, the ultraviolet radiation keratoconjunctivitis.

Research on Ultraviolet Impact on Eyes

French doctors found chronic exposure to ultraviolet cause pterygion, appearance of the typical yellow pigments of the nuclear cataract and the progression of retinal degenerations.[9]

Fordham University, New York City found Ultraviolet radiation as a risk factor for cataract, macular degeneration and damage to the retinas of children. The removal of these wavelengths from ocular exposure will greatly reduce the risk of early cataract and retinal damage[10].

UV radiation can produce photochemical lesions in the neural retina and retinal pigment epithelium. [23]

People who have a job that requires a lot of close-up work, and people who live and work in a hot climate with lots of ultraviolet sunlight exposure, may also develop premature presbyopia.

http://www.patient.co.uk/health/age-related-long-sight-presbyopia

Stevens MA, Bergmanson JP,College of Optometry, Univeristy of Houston did research and found UVR has most scientific support to affect the onset of presbyopia.

http://www.ncbi.nlm.nih.gov/pubmed/2677104

The Resonant Circuit in Fluorescent Lamp Ballast Generates High-frequency Electromagnetic Radiation that has impact on human body

1) cell carcinoma induction;

2) abnormal hormone;

3) intense calcium loss;

4) triggering dementia;

5) abnormal pregnancy and abnormal birth;

6) high blood pressure and heart disease;

7) electromagnetic hypersensitivity;

8) depression increase.

The Lamp Brightness Changes with High Frequency above 1kHz, the Flicker is Invisible Flicker.

PAR1789 of IEEE found Wwhether visible or invisible flicker can be a trigger for headaches, migraines, fatigue, epilepsy, and other neurological responses.

Flicker has been shown to degrade reading performance, provide a distraction or annoyance for sensitive individuals.

There has been emerging concern about health effects in lighting due to invisible flicker (IEEE PAR1789, 2010).

Most humans are unable to perceive flicker in light above 60-90Hz, but there still remain measurable biological effects above the critical fusion frequency.

ERG(electroretinogram) responses indicate that invisible flicker is transmitted through the retina, (Berman,1991).

Some researchers have shown that this flicker may lead to headaches and eye strain (IEEE PAR1789, 2010; Wilkins 2010)[11].

Research for high frequency cyclic light:

Recent work by Albert et al has shown the development of progressive stages of retinal degeneration and choroidal neovascularization after long-term intense cyclic light exposure in albino rats.[21]


reference

[7] Daniel T. Organisciak and Dana K. Vaughan, Retinal Light Damage: Mechanisms and Protection, Prog Retin Eye Res.2010 March;29(2):113-134 .

[8] Chalam KV, Khetpal V, Rusovici R,Balaiya S, A review: role of ultraviolet radiation in age-related macular degeneration, Eye Contact Lens. 2011 Jul;37(4):225-32. doi: 10.1097/ICL.0b013e31821fbd3e.

[9] Xhauflaire G,Uhoda E,Rakic JM, Eye and ultraviolet light, Rev Med Liege. 2005;60 Suppl 1:99-102.

[10] Roberts JE, Ultraviolet radiation as a risk factor for cataract and macular degeneration, Eye Contact Lens.2011 Jul;37(4):246-9.doi:10.1097/ICL.0b013e31821cbcc9

[11] Lehman, B.; Wilkins, A.;Berman,S.Poplawski, M., Proposing measures of flicker in the low frequencies for lighting applications, Energy Conversion Congress and Exposition(ECCE),2011 IEEE, Date of Conference:17-22 Sept.2011,Page(s):2865-2872

[12]Wilkins, A.,Veitch, J.,Lehman, B. LED Lighting Flicker and Potential Health Concerns: Energy Conversion Congress and Exposition(ECCE),2010 IEEE, Date of Conference: 12-16 Sept. 2010, page 173

[21] Albert DM, Neekhra A, Wang S, Darjatmoko SR, Sorenson CM, Dubielzig RR et al. Development of choroidal neovascularization in rats with advanced intense cyclic-light-induced retinal degeneration,Arch Ophthalmol 2010; 128(2):212-222.

[22] PN Youssef, N Sheibani and DM Albert, Retinal light toxicity, Eye (2011) 25, 1-14; doi:10.1038/eye.2010.149; published online 29 October 2010.

[23] Sparrow JR, Nakanishi K, Parish CA, The lipofuscin fluorophore A2E mediates blue light-induced damage to retinal pigmented epithelial cells, Invest Ophthalmol Vis Sci.2000 Jun; 41(7):1981-9.