Sensitive Methods for the Detection of Bjerrum and Other Scotomas

Selective damage to chromatic mechanisms in neuro-ophthalmic diseases I. Review of published evidence

“…An important advantage of such a display is that an 'equiluminous' test spot can readily be generated i.e. a spot which matches the surrounding screen in luminance but not in color (Feree et al, 1931). Because there is no luminance clue, the subject is forced to use chromatic processes to detect the spot and so the chromatic threshold is simply equal to the detection threshold (determined by varying the color saturation of the spot); this eliminates the criterion problems involved in measuring color-recognition thresholds and permits a direct comparison of chromatic and achromatic thresholds in the same experimental conditions.…”

Selective damage to chromatic mechanisms in neuro-ophthalmic diseases I. Review of published evidence

“…An important advantage of such a display is that an 'equiluminous' test spot can readily be generated i.e. a spot which matches the surrounding screen in luminance but not in color (Feree et al, 1931). Because there is no luminance clue, the subject is forced to use chromatic processes to detect the spot and so the chromatic threshold is simply equal to the detection threshold (determined by varying the color saturation of the spot); this eliminates the criterion problems involved in measuring color-recognition thresholds and permits a direct comparison of chromatic and achromatic thresholds in the same experimental conditions.…”

A convenient and practical means for studying light and color minima in any part of the retina.

“…4 are given curves of the limiting and median values of the light minima from center to periphery for a small group of nonpathologic observers and, by way of comparison, the results for two cases of glaucoma. 2 These determinations * Glaucoma has been selected for representation here because it is one of the most common causes of blindness and one that is attended by wide and varied disturbances in the light and color sensitivity of the retina, the mapping of which is one of the most important aids to the diagnosis of the disease and to the detection of its advance or recession (7). The disease is in general characterized by increase of intraocular tension or pressure which progressively destroys the functions of the retina.…”

Selective damage to chromatic mechanisms in neuro-ophthalmic diseases I. Review of published evidence

“…An important advantage of such a display is that an 'equiluminous' test spot can readily be generated i.e. a spot which matches the surrounding screen in luminance but not in color (Feree et al, 1931). Because there is no luminance clue, the subject is forced to use chromatic processes to detect the spot and so the chromatic threshold is simply equal to the detection threshold (determined by varying the color saturation of the spot); this eliminates the criterion problems involved in measuring color-recognition thresholds and permits a direct comparison of chromatic and achromatic thresholds in the same experimental conditions.…”

A convenient and practical means for studying light and color minima in any part of the retina.

“…4 are given curves of the limiting and median values of the light minima from center to periphery for a small group of nonpathologic observers and, by way of comparison, the results for two cases of glaucoma. 2 These determinations * Glaucoma has been selected for representation here because it is one of the most common causes of blindness and one that is attended by wide and varied disturbances in the light and color sensitivity of the retina, the mapping of which is one of the most important aids to the diagnosis of the disease and to the detection of its advance or recession (7). The disease is in general characterized by increase of intraocular tension or pressure which progressively destroys the functions of the retina.…”

Selective damage to chromatic mechanisms in neuro-ophthalmic diseases I. Review of published evidence

“…An important advantage of such a display is that an 'equiluminous' test spot can readily be generated i.e. a spot which matches the surrounding screen in luminance but not in color (Feree et al, 1931). Because there is no luminance clue, the subject is forced to use chromatic processes to detect the spot and so the chromatic threshold is simply equal to the detection threshold (determined by varying the color saturation of the spot); this eliminates the criterion problems involved in measuring color-recognition thresholds and permits a direct comparison of chromatic and achromatic thresholds in the same experimental conditions.…”

A convenient and practical means for studying light and color minima in any part of the retina.

“…4 are given curves of the limiting and median values of the light minima from center to periphery for a small group of nonpathologic observers and, by way of comparison, the results for two cases of glaucoma. 2 These determinations * Glaucoma has been selected for representation here because it is one of the most common causes of blindness and one that is attended by wide and varied disturbances in the light and color sensitivity of the retina, the mapping of which is one of the most important aids to the diagnosis of the disease and to the detection of its advance or recession (7). The disease is in general characterized by increase of intraocular tension or pressure which progressively destroys the functions of the retina.…”