do lights cause people to have fits???

[walkersworld]

i have a small factory with a 3 phase supple,every 2-4 weeks a member of my staff has a fit,i have alot of flourecent lights,after speaking to a qualified electrician he said i should change the lighting?at a very expensive cost.can anybody shed some light on this subject? is flouresent lighting harmfull???

 

[dave.m]

If it is just one member of staff who is suffering, do they only work in one particular area?
Can you change the lighting in an area surrounding their work place?

Fluorescent lights do flicker but it is almost unnoticable to the naked eye, it can, however, trigger epileptic fits when the cycle of flickering is changed by a variation in the 50 Hz cycle going slightly up or down or when a light tube is becoming worn.
dave

 

[securespark]

My first wife suffered from epilepsy.

I had to replace switch start fittings with Thorn HF ones to reduce her chances of fitting.

These came on instantly with no visible flicker.

When we went out she sometimes wore dark glasses to lessen the effects of flickering lighting.

Strobes are a complete no-no & even an emergency vehicle's blue lights could trigger a reaction.

 

[viewer]

HF "Electronic" fittings push up the frequency and don't give the same problem; although not expensive each, I guess a whole factory would be a different matter. This requires a risk analysis for the affected person - where do they go etc etc. You obviously care about the staff, so no criticism, but you have a legal duty to carry out the risk assessment and take appropriate action. Apart from changing the fittings, there are a number of things which will help. Most flicker comes from the end of the tube and a (paper) cover over the first inch or so at either end can make a huge difference. The surroundings can affect the effect. Stainless surfaces can give odd reflections as well as glare. The position of the light relative to the person can be important as can different spectacle frames (some frameless glasses act as a prism amplifying the effect from lights above the person). A tungsten or halogen desklamp (or equivalent) can help reduce the local effect of flicker giving a strobe effect and is recommended for rotating machinery for this reason.
V

 

[timtheenchanter]

contrary to popular belief, the number of people with epilepsy who are photo sensative is approx 3%, so a very low number.
Speak to your employee, they should be aware if they are photosensitive or not, and if there are other reasons behind it change of medication/stress, as there are many reasons for an increase in the number of seizures a person has.
It may turn out they are having more in general, in which case your lighting has nothing to do with it.
What type of tubes do you have in them, you may find a change of tube to a daylight, or warm may improve things.

Just for info, its more frequently the amber beacons that trigger seizures than the blues on emergency vehicles (its to do with the wavelength of the light.)

 

[Steve]

Just a query, wouldn't the lights being spread across 3 phases reduce the effect of the flickering and therefore the sensitivity of perception of the lights flickering? Because theres always full light at all times of the cycle.

I know in small rooms its not practical, but on a factory floor I'd expect it.

I did once work in a shop with 4-tube recessed fittings, the old switch start types, and i did percieve a flickering in these, and glasses do magnify the flickering. All it caused was a headache though.

As said though, changing the ballasts for HF ones will make a lot of difference (my new store has these. They are great )