What does someone with eyesight affected by LHON see?
It is difficult to give a simple answer to this. Eyesight varies from person to person, and for one person eyesight can vary from second to second! What someone sees also depends heavily on the quality of the lighting, the colours, the level of contrast in the image and so on. Seeing with damaged eyesight takes a lot of extra concentration, so feeling tired or ill can make a lot of difference as well.
This page tries to give some general guidance based on my experiences.
Many people with LHON have a dark patch in the center of their vision, rather than bright colours. If you have an Iphone, Ipad or Android Smartphone you might want to try the VisionSim app mentioned below, which simulates a dark central patch.
The centre of my vision is a constantly changing cloud of bright green, red, gold and yellow. I have vision at the edges, more in my left eye than my right.
Even at the edges, all images are slightly blurred and it is sometimes difficult to tell colours apart, especially red and green.
My visual acuity is less than 1/100 – in my left eye I can do some finger-counting and in my right I I can see a hand waving, but I can’t see an optician’s wall chart, let alone read the letters.
These two photos show what the impact of LHON can be on someone’s eyesight. Looking straight at someone, you cannot see their face or any detail.
The amount of eyesight lost will be different for different people. Using damaged vision is difficult, needing a lot of concentration and good lighting. Sometimes someone with LHON is left with small patches of better sight known as “Windows” or “Fenestrations”, but they will have to practise and re-learn how to make the best of these , rather than take vision for granted.
Here is another image with examples of how someone affected by LHON might see them.
Here are examples of the same image with different levels of central visioni loss.
Most people with LHON will have little or no colour vision. This is because we see colours most clearly in the centre of our field of vision, and that is the area most damaged by LHON.
You may be interested in looking at the standard Ishihara Colour blindness charts, which are circular patterns of coloured dots.
What you see depends on how well you perceive colours.
Iphone/ Ipad/Android App to simulate Vision Loss
This page was last updated August 30 2015
Photographs of beach in India by permission of James Leeder. Copyright (C) James Leeder