extreme light sensitivity

[John Smith]

Hi Brigid, that's an easy one. Simple physics really.

It's the difference between reflected light and direct light.

A keratoconic cornea is irregular, so light entering the eye through it is scattered more than normal. This scattering leaves the retina bathed in light, and has that "interrogation effect" In other words: stop it, it hurts

However, when you're reading off a piece of paper, you need to have excellent focus to get round the KC abberations. In order to do this, you could look though a pinhole, because light passing directly through the centre of any lens is not refracted at all, thus allowing a clear (if tiny and dim) image to fall on the retina. The better option is to bathe the paper in more light, causing a brighter light to appear to the eye. The iris then closes up, reducing your pupil to nearer pinhole sized. Thus, it is easier to read. Even if it hurts.

I think psycologically, if the brain is trying to see something, it will put up with the glare; yet when just looking, the glare is the thing that the brain latches on to. And the result is pain. So, keep those dark glasses on, except when reading!

Who said it was simple? Oh, that was me

[GarethB]

The other thig to remember is if you have KC or not you should always take regular breaks when using a computer and watching TV for that matter.

As you look at screen your blink rate goes down so less wetting of the eye which leads to irritation.

[Andrew MacLean]

Well, there you are!

Just for the sake of balance, let me say that Mac OS X ciomes with embedded software that enables the computer to read text aloud to the user. It is possible to define a degree of magnification, and by tapping a key move towards that degree of magnification in stages.

It is also possible to alter the colour combination on the monitor, and I have a video magnifier that enables me to place books and documents under a "camera" of some sort and have the text presented on my computer screen, either full or split screen!

This was the configuartion agreed by RNIB, JobCentre Plus and my employer and it has always worked for me.

The advantage of the larger monitor is not that it automatically renders the text size larger or more easy to read, but that it enables me to see more of the magnified text, so that I can read all of this panel without having to scroll!

Yours aye

Andrew MacOS user

[Carol Vines]

i too wear different shades of sunglasses all year round and have not yet found a pair that go dark enough in the summer, i even wear a pair to watch the tv on a bad eye day, which are quite regular

brigid - as for people making snide remarks print off the employer leaflet from here and offer it round work for them to read; i did this a couple of weeks ago and it seems to have done the trick for now

[Lia Williams]

Tim,
Just a thought, are your eyes more light sensitive than usual? If so have you done any of the following? Got a new lens, got something trapped under a lens which has irritated it, changed solutions, over worn a lens?
A few years ago my right eye was very sensitive - I was down to twenty minutes wear in my right eye and even then it was difficult to keep my eyes open. In my case it was a new lens which was slightly different to the old one (different manufacturer) that was causing the problem. I'd had extreme light sensitivity before due to misfitting lenses but as my new lens was a replacement for the old one I hadn't expected a problem. I hadn't a clue what the problem was and went to Moorfields A&E. I was told to leave the lens out for a few days before reverting to the old one while a new lens of a different type was prescribed.

[rosemary johnson]

Light sensitivity seems to be very common with KC - to a greater or lesser extent.
As does "night blindness", or inability to see in poor light.

I have dark glasses - ones from a "kit for the blind" mail order firm with tops and side pieces, borad brimmed hats, etc.
[Incidentally, does anyone know where I might be able to get a broad brimmed "silk colours" cover from my jockey helmet??]

If it's worse than usual, it could be either a lens problem such as abrasion, infection, a cold or otherwise feeling below par - or a hangover!
But if it's getting worse all the time, that's part of the condition, and unfortunately one that "the powers that be" still don't take properly into account.

As regards the computers:
1. try turning the colour scheme round so you have lit letters on a black background. The "accessibility options" in Windoze have setting to do this automaticly with one selection (try "high contrast black large") or you can make your own.
A black background reduces the total amount of the screen that is lit up and emitting light, so reduces total glare. Also if you see "haloes" round light things, you might find it easier, and needed less squinting, if it is the things you want to see (the letters) have the haloes, rather than having the background making the haloes over what you want to see.

2. you can get specialist software that will either a) read out the screen b) magnify and change colour scheme (and switch between colours/magnifications att he touch of a hot key) and c) both together. The big names you may like to look up are : JAWS for screen-reading; Supernova (combination, of HAL reading and Lunar mag/colour change) and WIndowEyes.
These are all for Windows. Macs have in-built voices, but you need to be able to see well enough to use a mouse to highlight what you want read and set it off. Proper assistive technology screen readers are on the way (allegedly) for Macs. There are also screen reader projects for Linux at varous stages.
If you are having problems at work, and aren't able to work fully, then you may be able to get Access TO WOrk to pay for specialist equipment. Your local Disability Employment Advisor (at the job centre) or RNIB should be able to advise.

Another possibility would be for Access to Work to fund some hours of a PA or "2support worker" to help with tasks you can't do alone with no eyes. This - and the effective use of a PA - is a whole other story, of course.

As regards the TV - I understand that some of the ?SKy TV channels now are broadcast with audio description (called "narration", IIRR) available on another channel (you have to set this up, and I think it can be put on headphones so as not to disturb other viewers). So you could follow the action without having to look so closely. There are campaigns to encourage TV companies (and film/cinema companies) to extent provision of audio description.
Rosemary

[Amarpal]

Brilliant information in this forum! I too suffer from light sensitivity- especially with the low winter sunshine. I find sunglasses a reasonable solution to this problem, although sometimes, it can still be a problem.

A quick question- am I able to get tinted RGP lenses? I have never thought of asking at the clinic before.

Another piece of advice about the monitors... I find that standard CRT monitors can be very harsh to the eyes. I would recommend a flat panel TFT monitor, as the light seems to be less harsh, but also clearer.

Thanks

[Andrew MacLean]

Yes

I wore tinted RGP's for years. Indeed, to make life easier my right lens was tinted darker than my left!

Light sensitivity and night blindness are both due to the same feature of the KC eye: the cone scatters light onto parts of the interior of the eye where no light ought to shine. this causes pain. similarly at night, although there is less light and it does not cause pain, it is still scattered so that less of it falls onto the cells at the back of the eye that react to the stimulus and transmit the signals to the back of the brain where they are processed as 'sight'.

Andrew

[Hannah Pye]

John you are correct about the high resolution of your screen, there is another help that might useful also, you can change your screen to black , and choose a colour that you can see.

[Amarpal]

Thanks Andrew, I'll ask about them at my next appointment. I am still under 19 and in full time education so the cost of my lenses are covered by the NHS. Would the NHS contribute to the tinting of my lenses too?