Sciascopy (from the Greek skia=shadow) is the examination of the eye by observing the shadow moving within the pupil under the illumination of the eye. Thanks to the examination, it is possible to determine the refraction of the eye.
Skiascopyis an examination that does not require the active participation of the patient. Sciascopy allowsto identify a visual defectby means of a beam of light projected by the skyscope at the bottom of the eye. The direction of the shadow's movement in the pupil depends on the eye's refraction, i.e. the refraction of light rays passing through all structures of the optical system of the eye (the cornea, the aqueous humor filling the anterior chamber of the eye, lens and vitreous body).
Skiascopy: the course of the study
In order to accurately determine the refractive error and select glasses on this basis, you need to "shock" the accommodation (ie the eye's ability to adapt to good vision from various distances) in the examined eye with the use of eye drops, eg atropine. This eye examination is done in the darkroom using an apparatus called a slicer. It is a cylindrical device approximately 20 cm long. You sit 1 m away from your doctor who directs a beam of light from a slascope to your eye into your eye. The doctor observes the changes in the illumination of the pupil by the movement of the emerging shadow. In hyperopia, the shadow moves in line with the light of the skiascope, in myopia - vice versa. Then the doctor puts the so-called skiascopic slats, equipped with a row of focusing (positive) and diffusing (negative) glasses of increasing force. With the help of these lenses and changes in the movement of the shadow, the refraction of the examined eye is determined. If you suffer from glaucoma, please inform your doctor before the skiascopy.