Category: S

Refraction of the eye referred to the primary focal point of the eye and corrected by a lens placed at the eye’s primary focal plane.  

A method of illumination used in slit lamp biomicroscopy, in which the source and the microscope are placed at equal angles from the normal to the corneal surface, so that the surface observed will be illuminated by the image of the source. The reflection of sound waves from the surface of an internal structure, which…

Blurred vision occurring after contact lenses have been removed and replaced with spectacle lenses, due to temporary deformation of the corneal surface.  

Solution in which contact lenses are placed when not being worn, in order to maintain hydration of the lenses and to resterilize them.  

A back surface curve of a contact lens which is just peripheral to the base curve, is a certain number of millimeters (or diopters) flatter than the base curve, and averages 1.0 mm. or more in width.  

A method of llumination used in slit lamp biomicroscopy, in which the slit beam is directed toward the limbal part of the sclera from a wide angle, causing light to traverse the cornea by total internal reflection.  

A corneal lens having a scleral flange which stabilizes the lens so that residual astigmatism may be corrected with a front surface toroidal curve.  

A test of the quantity of tear secretion which makes use of a filter paper strip inserted into the lower fornix. Normally, 10-15 mm of the filter paper will be moistened within a period of five minutes. The use of an absorbent paper placed in the conjunctival sac as a test for patients with ocular…

Smoke that comes from a burning cigarette.  

Synthetic depressants developed for medical use. Drug that depresses central nervous system activity, relieves anxiety, and induces sleep. Barbiturates, minor tranquilizers (e.g., diazepam and chlordiazepoxide), chloral hydrate, and many other drugs act as sedative-hypnotics.