Color Vision by Atikur Rahman (dept. optometry, RIPANS)

This presentation include all about color vision, types of color vision defect & test , patient selection, management of color vision defect etc.

1. COLOR VISION PRESENTED BY ATIKUR RAHMAN Department of Optometry, RIPAN S

2. What is color vision? Color vision is an ability to distinguish among various wavelengths of light waves and to perceive the differences in hue.

3. COLOR VISION DEFECTS It is a reduced ability to distinguish between certain colors. Males are affected more than females. TYPES OF COLOR VISION DEFECT : Inherited color vision defect Acquired color vision defect

4. COLOR VISION TESTING Color vision test helps to identify red-green and blue color blindness. TYPES OF COLOR VISSION TEST: Pseudo Isochromatic plates Arrangement Tests Anomaloscopes

5. PSEUDO ISOCHROMATIC PLATE TESTS (PIC) PIC tests are designed on the basis of color confusions made by persons with color defects. The test is in the form of booklet. Each figure is made up of dots that vary from the background in hue as well as brightness.

6. PIC plates are designed in 4 different plates Transformation Plates Vanishing Plates Hidden Digit Plates Diagnostic Plates

7. TYPES PIC A) Ishihara color plates:

8. Ishihara is the most popular PIC test & comes in 3 different forms 16 plates,24plates & 38 plates. The test should be performed under standard room illumination. The patient should recognize each plate at 75 cm within 3 sec.

9. B) American Optical Company (AOC) Plates: It comprises of a set of 15 plates. It is used as a screening test.

10. C) Divorine test

11. Divorine test It consist of set of 15 PIC plates. It is use for identifying patients with hereditary red-green color deficiencies. The test booklet consist both PIC plates and a color naming test.

12. ARRANGEMENT TESTS These tests are most useful for both inherited & acquired color defects. Types of Arrangement Test Fransworth-munsel D-15 Test Fransworth 100 Hue Test

13. Fransworth-munsel D-15 Test

14. Fransworth-munsel D-15 Test It is designed to distinguish the functionally color blind from the moderately color defective & the normal. It detect not only red-green anomalies but also yellow-blue anomalies. It consist of 15 different colored caps.

15. Fransworth 100 Hue Test

16. Fransworth 100 Hue Test Fransworth 100 Hue Test(FM 100-hue) is a sensitive test. It consist of 85 caps located in 4 trays of 21 or 22 caps each. Two reference caps are fixed at two ends of each tray.

17. Nagel Anomaloscopes

18. This instrument is based on Rayleigh equation. Commonly used in the diagnosis of red-green deficiencies. Assesses the observers ability to make a specific colour match. It can be distinguishing between dichromates and anomalous trichromates.

19. ADVANTAGES AND DISADVANTAGE OF NAGELS ANOMALOSCOPE TEST ADVANTAGES Its superiority in distinguishing between dichromates and anomalous trichromats. It remains the standard for classification of the four types of red green defects. DISADVANTAGES Rarely used because of its difficulty to administer and high cost.

20. PATIENTS SELECTION FOR THE COLOR VISION TEST Choose patients who complains about the differences in colour vision between two eyes. Test any patients who exhibit a sign of abnormality in fundus. Choose patients who complains of unexplained reduction in visual acuity.

21. MANAGEMENT OF COLOR VISION DEFECTS It is important to counsel the patient for colour vision defects. The practitioner should carefully listen to the patients complain related with colour deficiency. There is no care for inherited colour defects.

22. Management of Inherited color defects Patients Counseling. Color Filters.

23. Management of patients with Rod Monochromatism The Rod monochromats usually have poor visual acuity along with photophobia.

24. Management of patients with acquired color defects Acquired color defects may affect each eye differently. The color vision testing should be done on frequent intervals to monitor the success of treatment.

25. THANK YOU