Stereo Acuity Test

Bagolini Striated lenses in handheld frames

Striated lenses in handheld plastic frame with temples. Bagolini type lenses for testing and diagnosis of ARC orthoptics.

The Lang Stereopad, similarly to the  Lang Stereotests I and Lang Stereotest II-R, combines Random Dots with a lenticular surface but offers more sophisticated assessments of stereopsis. Magnetic test cards are shown individually or in pairs on a handy red double-sided test panel. The test does not require specific glasses and is highly sensitive for global stereopsis. It has no monocular clues and is ideal for preferential-looking testing of infants and preverbal children.

Intended use and main features
Lang-Stereotests are orthoptic products for binocular diagnostics and screening of disorders of stereoscopic vision in adults and children, for medical professionals. The Lang-Stereotest is used for rapid screening of stereopsis vision in all age groups from 6 months of age. Since loss of stereopsis is considered a key symptom of amblyopia (lazy eye), failure to recognise random dot stereograms may indicate a previously undetected, treatable disorder of binocularity (e.g., microstrabismus, anisometropia). Lang-Stereotest  have proven to be highly specific and highly sensitive for stereo vision. Thanks to the unique combination of random dots and a lenticular lens, no special glasses are needed, and the eye movements of the subject may be easily observed.

The test exists in the versions Lang-Stereotest I and II, and the revised versions I-R and II-R.

An alternating polarized lens flipper that is used with vectograms and tranaglyphs to reverse BI/BO demands.

First launched in 1983, it is used in orthoptic and ophthalmic clinics and by optometrists world-wide.

• Tests for stereopsis using natural vision, with no special glasses. It has three transparent plates, which are presented to the patient one at a time against the clear background provided by the fold-down flap of the storage box.
• Tests for stereopsis, even if reduced vision or amblyopia is present because of the coarse texture elements included in the pattern.

The Lang-Stereotest^® II is an easy-to-use examination instrument designed for screening, i.e. early detection of spatial vision problems in children.

The Lang-Stereotest^® II is a supplement to the proven Lang-Stereotest^® I (Star, Cat, Car) and is also used to test binocular vision according to the same principle. In addition to three figures that are only visible binocularly (crescent moon, car and elephant), there is also a contoured star that can be seen with one eye. The individual figures appear to be set off from the background at different distances.

Many users had requested another stereoscopic examination card as an alternative to the Lang stereo test^® I. In version II, the random dots are smaller and less dense. The disparities are chosen a little finer, namely 200 arc seconds for the moon, 400″ for the car and 600″ for the elephant at an observation distance of 40 cm. The star, which is also visible monocularly and has a disparity of 200″, is intended to improve diagnostics in young children by increasing attention and reaction. In addition, subjects without binocular vision remain less disappointed.

Note: the LANG-STEREOTEST does not measure visual acuity and does not substitute for an ophthalmologic examination. A negative test result indicates only a lack of stereoscopic vision at the time of examination.