When optometry becomes child's play.
When optometry becomes child's play.
The work of an optometrist is certainly not all child's play, but over the years play has proved to be an effective technique when testing the sight of children.
It is important to test children's sight because young children sometimes struggle to understand their own visual development, and may 'present' at a consultation with congenital or acquired disorders that first appear in childhood.
Monoptotypes - These French letter cubes from circa 1909 are like children's building blocks. They were designed by a certain Dr A. Bourgeois of Rheims. Preschool children might be asked to point at blocks containing shapes instead of letters. A version of that test is known as Ffook's Symbol Cube.
The cube is particularly useful for the assessment of visual acuity (VA) in very young children or children with impaired learning since the test does not rely on spatial orientation or intelligence. Only three basic symbols were employed. Supplying pairs of cubes meant that each shape could be represented at each Snellen size.
Optometrists must be capable of working with young and old alike. They are trained in the use of distraction techniques and how to interpret the responses of infants, including those from patients who may be experiencing learning development problems. Early diagnosis of underlying conditions such as dyslexia may result.
To help children of reading age test charts might include pictures of animals beginning with the same letter e.g. 'cat' for 'c'.
This 'Horse chart', supplied by Hamblin in 1952 (shown on the right) serves a different purpose. The legs, which decrease in thickness down the chart, have to be counted. The third row down shows most obviously how this chart is related to the iliterate 'E' chart.
The Sjögren Visual Acuity test was considered suitable for children even as young as two. This English version of the famous Swedish 'hand' test was redesigned for use at 6 metres (instead of the 5 metres favoured elsewhere). The optician held up the card and the child had to hold up his or her hand with the fingers pointing in the same direction. The largest hand in the set is illustrated here. The size of the fingers on the chart conform to the Snellen specification whilst the surfaces of the cards were, very sensibly, designed to be washable! (The child might be invited to practice beforehand by placing a hand over the card) c.1957.
'Ship' Test Chart (shown on the left) - the child must count the funnels, 1950s.
These coloured overlay sheets ('Mint Green' and 'Aqua' blue - shown on the right) were developed by Dr Bruce Evans, FCOptom, DipCLP, DipOrth at the Institute of Optometry in 1995 as a temporary test to see if colour will help the patient against blurring, distortion, discomfort or headaches. If the overlays worked then coloured lenses could be prescribed (to a much more precise tint as worked out from the use of an Intuitive Colorimeter). Whilst the test was suitable for both adults and children the educational benefits for the child so helped by them could be enormous.
Sometimes it is the practitioner who is distracted by the child!
The illustrations in the above gallery are taken from a series of cartoons drawn by the Production Company behind a Directorate of Optometric Continuing Education and Training (DOCET) video made to coincide with a conference on child practice organised by Mrs Angela Bishop, FCOptom.
Did you know?
Toy manufacturers are now studying research into how babies see in order to choose the best colours to use for their latest products. Research in the Department of Psychology at the University of Surrey has concluded that babies can demonstrate a measurable preference for certain colours. Black and white toys are ideal for newborn babies since they see in black and white during the first few weeks. (Source: Optician, 11 March 2005).