Applications of neural networks to colour recognition.

Colour specification and matching are important tasks used in a number of different industries. However, current methods can employ very complicated, elaborate pieces of laboratory equipment which are not portable, such as spectrophotometers with combinations of calibrated light sources and a large number of narrow band filters. Simpler, portable devices are typically not sophisticated enough to give a high degree of quality control due to the less sophisticated light sources and the necessarily smaller number of filters employed.

A comparison of the blue color mechanism in high- and low-tension glaucoma.

Twenty-five eyes of 25 high-tension glaucoma patients and 25 eyes of 25 low-tension glaucoma patients matched for similar visual field defects had their spectral increment threshold measured. Patients with high-tension glaucoma showed significant losses in both chromatic and achromatic sensitivities when compared with low-tension glaucoma patients. The results support the hypothesis that there may be different mechanisms of damage in glaucoma.

Correlation between color vision and highest intraocular pressure in glaucoma patients.

We examined 75 glaucoma patients to determine the relationship between losses in color vision and their highest intraocular pressure. The losses of blue chromatic (P less than .0001) and achromatic (P = .

Color vision and retinal nerve fiber layer in early glaucoma.

We tested 47 eyes in 47 patients (ten normal subjects, 15 with suspected glaucoma, and 22 with glaucoma) with the Pickford-Nicholson anomaloscope to assess the retinal nerve fiber layer and measure color vision. The 47 subjects were randomly selected from a group of 132 for whom Farnsworth-Munsell 100-hue color error scores were known. The yellow-blue and green-blue anomaloscopic matching ranges correlated significantly with diffuse retinal nerve fiber loss.

Acquired color vision changes in glaucoma. Use of 100-hue test and Pickford anomaloscope as predictors of glaucomatous field change.

A five-year follow-up of eyes with elevated intraocular pressures, but without field defects, in which the color vision had been assessed by the 100-Hue test and an anomaloscope was carried out. Field defects developed in eight of 42 eyes with a low 100-Hue score, whereas field defects developed in ten of 13 eyes with a high abnormality in the 100-Hue test score. In the case of the anomaloscope (Pickford Nicholson) scores, field defects developed in four of five eyes with poor yellow-blue scores, whereas similar field defects developed in only nine of 40 years with a normal yellow-blue scores.