Amblyopia - lazy eye or squint
Vision is a learned experience. A child is born with a pair of eyes but not a visual world. If it is learned, then it can be relearned. When an eye fails to develop properly, the ability to see clearly is not developed. Perhaps it points in the wrong direction (squint) or is a different dimension (long-sighted in one eye only when the brain favours the better eye). Traditionally this will have been patched in childhood under the care of an Orthoptist usually based at a hospital. This stimulates the retina forcing recognition and improving the acuity (line of letters). It is better still to integrate the two eyes so that they work together creating 3D vision or stereopsis. This gives an appreciation of time and space in the world around you and is an advantage when driving and playing sport. It was thought that after 8 years old it is too late, but it has been shown by Dr Susan Barry who describes this in her book ‘Fixing my Gaze’. You can see her TED talk here.
Ruth Perrott achieved stereopsis in her late 50’s and can vouch for the benefits.
If an eye has been ignored then it will not have learned to recognise the letters. Quite often there is a high refractive error (would need strong glasses) which has not been corrected. We have an office based therapy system called VTS4 which offers different images to the different eyes and promotes each eye to register and function not only independently but in harmony and forming binocular vision.
We also now have the Vivid Vision (see www.seevividly.com) Virtual Reality headset which presents a brighter image to the weaker (student) eye, and dulls down the image for the leading (teacher) eye. This is available as a home therapy where you buy the hardware according to the website and the software and its monitoring is supplied by VisionCare Development.
There are many other games and activities away from the computer to blend into daily life. We first have to convince the brain that it has two eyes to cope with and not just one.