Being the mother of a 2 year old daughter, I experienced first-hand the ever-present worry – does my baby have a squint?
Even though in my training as an optometrist, I learnt how unstable the eyes are in the first few months of life, I was faced with the dilemma – are her eyes ever going to look straight??
What reassured me was what an eye specialist once told me – “Squints worry parents a lot more than they worry doctors!!”
Now for a brief optometry lesson. . . .
At birth, the eye is not fully developed in term of its size and full-seeing potential. Babies cannot see fine detail: in fact studies show that they would not even be able to see the top letter on a vision chart, and would be able to see large checkerboard patterns equivalent to 4 times the size of the top letter! This helps to explain why their eyes are so unstable, since it is difficult for them to fixate on any objects. Yet luckily, they can see Mom’s face at about 30cm which is important for bonding while feeding! By 6 months, their vision is 8 times better and they can make eye contact with a person entering the room.
The eyes can be compared to 2 digital cameras, which need to be linked by a wiring system to a computer, aka our brain, in order to see the pictures clearly. As long as each eye produces a good quality picture, the brain will put the 2 together and this creates a 3D picture. If a picture from 1 eye is inadequate, such as out of focus or in the wrong position, the brain will ignore it and will use the clear picture coming from the other eye.
This complex wiring from the eyes to the brain develops properly within the first 6 years of life, and it is VITAL that the brain receives good quality “pictures” from BOTH eyes. Therefore, a significant refractive error, for example if a child is short-sighted or far-sighted in 1 eye: a squint or other abnormality in 1 eye, can markedly affect this process. This is why ALL children should be examined during this critical time frame, and the sooner the better (before the proper wiring is laid down properly.) This is why I feel preschool vision screening is so important.
This is why no matter how worrying it appears, there is no need to have a baby examined before 6 months of age, unless you are advised by your paediatrician. Family history of squint or “lazy eye” necessitates early examination by an eyecare professional – 18 months of age has been suggested. If a squint is quite severe and constant, further investigation should be sought sooner.
A squint or strabismus affects 3 – 4 % of the population. The most common type is where the eye “turns in” and if this type occurs in the first 6 months, it is usually large and easily noticed. What complicates matters is that small babies have a fold of skin, called the epicanthal fold on both sides of the nose at the bridge. This deceptively makes the nasal part of the “white of the eye” appear narrower than the side closer to the ear. We call this a “pseudo-squint”: ie, it is not a true squint but can appear as one! As the baby grows, this skin helps form the bridge of the nose, and the illusion of a squint disappears. . . .
Surgery is normally required if the squint is very large, to ensure the best chance of visual development, and is therefore done early in life. 60% of convergent (inward) squints can be corrected by wearing spectacles, as this type of squint is often associated with far-sightedness or hyperopia. The remaining 40% of those squints will require both surgery and spectacles.
Leanne Fenwick, Optometrist: R & F OPTOMETRISTS
Shop 141, The Crescent Shopping Centre
(031) 5665696/ 0825578237