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SACCADE
Involuntary movement of the eyes. A saccade is rapid (0.01- 0.05 second) and of short range (1 to 25 sixtieths of an arc). |
SCLERA
The visible casing that holds the eye, better known as the “white of the eye”. (see EYE) |
SINGLE-VISION LENSES
Lenses for correcting ametropia. They are also the oldest method of correcting presbyopia. The power of the lens is the same across its entire surface. |
SNELLEN TEST-TYPES
Optotypes made up of letters of various sizes in which the thickness of the line is equal to one fifth the letter’s height. |
SOLAR RETINITIS
Retinitis resulting from excessive exposure to sunlight (e.g. at the seaside or during a solar eclipse) and characterized by a central scotoma that generally disappears over time if the exposure was not overly intense. However, in many cases there is a permanent mild loss of visual acuity. |
SQUINT
Term commonly used to refer to strabismus. |
STRABISMUS
Also called “squinting”. This abnormality in binocular vision is characterized by a deviation in one eye or both. It can be corrected from the age of five to six months. |
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