Live Life Team
Tests for hearing and vision impairment should be carried out on newborns too. This prevents further loss of vision or hearing. Children need to have this test on routine basis until they attain four years of age. When their primary schooling starts, the school arranges for such tests. The secondary school children are tested for colour blindness too. When children complain about their problems with their vision or hearing, the parents should have them diagnosed as soon as possible.
How hearing tests are performed
Doctors screen the newborn babies through Automated Otoacoustic Emission (AOAE) test. They place an earpiece in the outer ear of the child and produce click sound, to which the inner ear reacts. A computer records this reaction and analyses it. They can perform this test even when the child is sleeping. The downside of this test is that results are not always clear. An alternative to AOAE test is Automated Auditory Brainstem Response (AABR) test. This involves placing small sensors on the head and neck of the baby. The doctor plays click sound through the earphones and the response is analysed through a computer.
Doctors perform distraction test if the child is six months old, or above. Child with normal hearing responds by turning the head. For children aged two years or above, response is tested by telling an object’s name softly. The child points to the object if it has normal hearing.
The primary school children can undergo sweep test. Different speech frequencies and volumes are played through earphones. Doctors assess the hearing capacity, based on the response of the child.
How vision tests are performed
A wide range of tests is available for detecting the vision impairment of various types. A physical examination of the eyes of newborns may help detecting obvious defects such as redness, cataract and cross-eyes. The doctors beam light on the eyes to check pupil reflex. The pupil, which is normal, should shrink in response to brightness.
Use an opthalmoscope, doctors direct light into the eyes of the baby and check for red reflection. If the reflection is white, the child is referred to a specialist at once.
To check if the newborn baby’s eyes follow a movement, doctors move an interesting object, in front of the baby.
A rolling ball test is used to check the focus and sharpness of eyesight of babies who are nearing two years of age. White balls of different sizes are rolled on the floor to assess the range of vision and ability to identify a small object. We can check the sharpness by placing buttons of various colours, on the floor. Child with a normal vision tries to reach the buttons. For children of five years and above, you can place a chart with rows of letters at a distance of several metres from them. The size of the letters should decrease, down to the last line. You can ask them to read loudly, each row. This test helps assessing their sharpness and focussing ability.
Doctors test the visual field of a child by moving a wiggly finger into the vision field of the child.
Last, but not the least, is the colour blindness. Doctors perform Ishihara colour vision test. Doctors ask the child to interpret two different colour dot images. If the child recognises the images and identifies these colours correctly, the child has no colour blindness. If the child is not able to see the image, the child has colour blindness.
