Vision assessment and eye examinations are important for detecting visual impairment in children. Impaired vision in children may cause issues with school performance, or may lead to blindness. Children with high risk of eye problems may be due to premature birth, history of congenital cataracts (clouding of the eye lens), metabolic or genetic diseases, and neurologic disorders should be assessed for visual defects. Therefore, careful assessment of the ocular system helps in identification and treating various visual defects in children.
In infants, usually eyes are assessed immediately after birth and continually at all routine supervision visits. All infants should be evaluated by the age of 6 months for ocular alignment, presence of an eye disease, and eye fixation. The infants’ eyes should be checked till the age of 3 or 4 years until the visual acuity measurement (vision screening) can be performed.
Your physician will examine the eyes based on the age of your child.
Your doctor will evaluate the symmetry and function of the eyelids and orbits (bony cavities occupied by eyes and its muscles). If the orbit of one eye is disproportionate compared with the other, your doctor will further examine the eye for the presence of tumors, or abnormalities of the orbital bones.
Your doctor will evaluate the sclera (white part of the eye), conjunctiva (transparent tissue covering the sclera), cornea (transparent covering on the coloured part of eye), and iris (coloured part of the eye) externally with the help of a penlight. Your doctor will check the child’s eye for persistent discharge or tearing in the eyes.
The ocular alignment is evaluated in older infants as the young infants find it difficult to fix on a target and follow it. The ocular alignment tests are conducted to differentiate true strabismus (abnormal alignment of eyes) from pseudostrabismus (false appearance of crossed eyes).
These ocular motility tests include:
The eye pupils have to be round, equal, and reactive to light. Slow reaction of the pupils may be due to retinal or optic nerve (transfers visual information from retina to brain) dysfunction. If the size of one pupil is larger than the other, or both pupils are larger than 1 mm, it indicates a serious neurologic disorder and requires further evaluation.
The red reflex test can detect abnormalities in the back of the eye, and opacity in visual axis. This test is performed in a dark room to increase pupil dilation. Your doctor will focus the ophthalmoscope on each pupil at about 12 to 18 inches away from the eye and simultaneously view both the eyes. Bright reddish-yellow or light gray indicates the red reflex. Presence of white reflex, dark spots on the red reflex, dull red reflex, and lack of red reflex indicates need for further evaluation.
This test should be performed in children above 3 years of age; in case if the child’s doesn’t cooperate, another attempt should be tried after 4 to 6 months.
The child will be asked to read the lines on the chart and identify at least 4 of the 6 symbols on the line correctly. The lines on the chart can be moved to a critical level until the child identifies symbols correctly. This procedure is performed for each eye by covering the other eye at a time. Children with corrective eyeglasses should be screened wearing the eyeglasses.
The tumbling E or HOTV test can be used for children who are unable to identify letters and numbers. This test consists of wall charts composed of tumbling Es or Hs, Os, Ts, and Vs. Your doctor will point a letter on the chart, and the child will be asked to identify the correct matches on the testing board.
These tests consist of flash cards with pictures on it, for example a house, cake, telephone, or horse. The children will be asked to identify these pictures before actual visual testing. In the Allen card test, the acuity score is calculated based on the distance at which the child is able to identify pictures correctly. In the LH symbols test, visual acuity is recorded based on the smallest size of the symbol identified by the child at a distance of 10 feet.
Your doctor will examine the optic nerve and retina by using an ophthalmoscope. Ophthalmoscopy is performed in children who are co-operative and able to fix their eyes on a toy.