Page 7 - NAME OF CONDITION: REFRACTIVE ERRORS

loses interest in performing near work like reading and writing leading to a compromise in
quality of life.

The evaluation of refractive errors requires an assessment of both the refractive status of
the eye, the patient’s current mode of correction, symptoms, and visual needs. As
emphasized repeatedly, refraction is often performed in conjunction with a comprehensive
ophthalmic evaluation. A thorough history with a special focus on the vocational needs of

the patient should be asked for and kept in mind before finalizing the prescription. The
examination should include both undilated and dilated evaluations. While pupillary
reactions, ocular alignment and movements, visual field evaluation (in indicated cases) and
dynamic refraction can be performed on a reactive pupil, posterior segment evaluation and
cycloplegic retinoscopy and refraction can be done after dilating the pupil.

b) Investigations:

1. Visual acuity testing

Distance visual acuity is usually measured in a dimly lit room as the patient looks at a
chart of high-contrast characters. It should be measured separately for each eye with
current correction. For clinical purposes it is desirable that test chart luminance not be
less than 80 cd/m2. It is desirable that the luminance level employed be specifiable.
visual acuity testing conditions should be standardized in each examination room and
at each visit, so that the same viewing distance and lighting conditions are used. Near
acuity is usually measured while the patient looks at a well-lit reading card of high-
contrast characters held at a specified near working distance, typically 14 inches or 30

cm

Nonverbal child (upto 1 year)

Estimating visual acuity in a non verbal child is a challenge. It should comprise of assessing
the following parameters.
1. The assessment for this age involves evaluation of ocular fixation and following to
appropriate visual stimuli: for an infant under 4 months of age, the examiner’s face or
the parent’s face is used as a target. For older infants, appropriate toys can be used to

induce fixation. Attempts should be made to assess the quality of the fixation response
(central, eccentric, steady, unsteady, maintained) to the targets used. Even a subtle
difference in the ocular fixation response of an infant with an otherwise normal eye
examination requires monitoring to evaluate the presence or development of
amblyopia.
2. Ability to fixate a light held at 33cm.is assessed
3. Blink reflex in response to sound is observed.

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