The two roving wanderers Strabismus (or crossed eyes) and Amblyopia, also known as Lazy Eye, are the highwaymen of the eyes, always roaming, stealing good and accurate vision, and seldom staying in the same place for very long. Both conditions put the two eyes out of focal sync with each other, and in the process affect the integrity of the information each of them sends to the brain for processing, according to Australian behavioural optometrists Jacqueline Gattegno, and Gary Rodney.
Both eye conditions are common in young children, with strabismus affecting about 4% of those under six, and lazy eye impacting up to one out of every two young children, and about 3% of the overall population.
How the Unlikely Pair Do Differ
While the two seem (and are) very closely linked, and sometimes, actually wreak their havoc on perceptual vision together, where they do differ considerably is in how they operate, and in that one of them can cause the other, says Rodney, fellow of the International Academy of Orthokeratology and Myopia Control (FIAOMC). He says strabismus is known to be one of the major causes (though not the only one) of amblyopia, and it’s development into a more severe form, which can ultimately lead to a loss of vision in the lazy eye.
Strabismus, an eye-alignment problem which can start at birth or be acquired later, develops either when body or brain problems interfere with the function and control of the muscles outside the eyeball that are responsible for eye movements; or in the nerves and vision centres which control vision. It leaves the eyes unable to focus on the same space or in the same direction at the same time. Instead it causes one eye (or sometimes both) to move in different directions, turning outwards, up, down, or inwards, while the other looks straight ahead.
The ultimate in rovers, strabismus, unless it’s the very severe constant version, can disappear for some time and even for years, only to return later in life, when muscles have started to weaken, Rodney says.
Amblyopia, labelled as “lazy eye”, usually starts during infancy or early in childhood, and is all about visual acuity or eyesight. It’s the result of poor vision development in one eye (or, occasionally, both), and is often the result of imbalance in the muscles that position the eyes. It blurs vision, and keeps it that way even when wearing spectacles.
Consequences of These Wanderers
According to Rodney, the outcomes of both eye conditions are the same – there’s interference and disruption of the connection between the eyes and the brain which is essential for the visual system to work. When two eyes function normally, the versions of the information they receive from light rays and send to the brain for processing, will match well enough for the brain to complete the process. When the two eyes see differently, their messages will be confusing and less understandable, making it difficult for the brain to interpret or process them.
Amblyopia on it’s own, or when paired with strabismus, becomes a real threat to vision (and itself) when, as often happens, the brain gives up on the eye that continuously sends confused messages, and ends up ignoring it. Instead, the brain favours the eye which consistently sends processable information. This can result in the “lazy eye’s” vision worsening still further, and when strabismus teams up with it, or is the cause of it, total loss of vision in the lazy eye becomes very likely, according to Rodney.
Strabismus, with its wanderings, can negatively affect the depth perception which adds the 3D aspect to viewed objects, as well as impacting on the peripheral (or side) vision, leading to double vision. Other symptoms include jittery vision, eye strain and headaches which make it both uncomfortable and tiring for someone to read, and factors which can be misinterpreted as being evidence of learning difficulties, disorders, or disabilities.
For more information on strabismus, amblyopia, or the ways that vision therapy can be used to treat them without surgery, or to make an appointment for a regular eye check, visit the Smart Vision website: Optometrists Sydney: Optometry Services For Children and Adults | Smart Vision; for specific information about Myopia treatment and prevention visit Myopia Prevention: Solutions, Control And Treatment In Sydney; and for detailed information about Myopia Treatment visit Orthokeratology In Sydney: The Non Surgical Alternative.
To book an appointment for a thorough eye check-up, click here or Call the Bondi clinic on (02) 9365 5047 or the Mosman clinic on (02) 9969 1600.