The refraction measurement is the visual examination commonly, and improperly, called "vision measurement". Usually, it starts with determining visual acuity. If visual acuity is compromised, or there are symptoms of visual fatigue or alteration of binocular vision, we proceed to determine the presence of a possible ametropia, or an optical defect that blurs the images on the retina. The task of the refractive examination is to determine the extent of the defect and to prescribe its optical correction.

The refraction measurement is followed by an ocular biomicroscopic analysis, first in miosis, then in mydriasis, at the slit lamp to evaluate the integrity of all the anatomical structures that make up the eyeball. And finally the measurement of eye tone.

Orthoptics is the discipline that deals with the assessment of ocular motility disorders and binocular vision and the treatment of amblyopia.

Orthoptic evaluation is necessary whenever you are faced with a pathology such as strabismus in both pediatric and adulthood, or in the presence of symptoms such as diplopia (double vision).

The examination of the visual field is performed with a computerized device that measures the sensitivity of the retina to light, showing the subject a light stimulus. The subject in question, keeping his gaze fixed on a central point, will respond, via a button, whenever he will be able to appreciate the stimulus presented to him in the whole field of vision that we intend to test.

Computerized perimetry is an integral part of the diagnostic process of neurophthalmological pathologies such as glaucomatous disease, opticopathies, etc.

The small patient (0 to 7 years) in Ophthalmology represents a distinct entity compared to the adult. For this reason, from the first evaluation, adequate diagnostic approaches should be used: to use visual stimuli and small objects for which the pediatric patient can express a certain interest (luminous stimuli, small objects that emit sounds, etc.). In addition, the ophthalmologist must have considerable experience in this field.

The complete pediatric eye examination undoubtedly involves evaluation also in mydriasis (instilling a mydriatic eye drops during the visit). In some cases, the assessment in mydriasis will be followed by an assessment in atropinic cycloplegia.

How do you evaluate the correct functionality of the visual system? When is it necessary to investigate these aspects?

Psychophysical investigations (assessment of visual acuity, campimetry and perimetry, examination of chromatic sense and sensitivity to contrast) are based on subjective responses provided by the patient, and do not allow to selectively identify which structures of the optical pathway are functionally compromised.

Electrofunctional investigations (electroretinogram-ERG, electroretinogram from PERG pattern, visual evoked potentials-VEP) provide selective information on the functionality of the various segments of the visual pathway. They constitute an objective, non-invasive semeiological method.

Electrophysiological investigations are fundamental for the diagnosis of genetic and acquired retinal photoreceptoral degenerations, as well as in neophthalmological diagnostics, in the presence, for example, of alterations in the conduction of the optic nerve and of the posterior optic pathways.