ORDER : The petitioner herein is one among the candidates who was selected to the post of Assistant Engineer (Electrical) and allotted to SC/Karur Electricity Distribution Circle, under the Backward Class - Muslim / BC(M) category on merit basis. Based on the Assistant Executive Engineer's letter dated 15.04.2017 stating that the petitioner had "colour blindness", he was referred to the Medical Board/MGM Trichy, Ophthalmology Department to verify his fitness to work as an Assistant Engineer. The medical report dated 23.02.2018 of the Regional Medical Board, Thanjavur had opined as follows :- “His occular examination RE Distant vision 6/6 LE- 6/16 Further examination BE - Normal. Both eye – colour vision defective”. 2. The medical report also stated the petitioner's fitness to work as Assistant Engineer (Electrical) cannot be opined since norms regarding colour vision was not provided by the Employer. Consequently on 14.03.2019, the respondents had referred the petitioner to the Regional Medical Board, Thanjavur Medical College Hospital by enclosing the work norms of Assistant Engineer (Electrical) and requested the Medical Board to certify with regard to his fitness to perform his duties as an Assistant Engineer. Once again, the Medical Board of Thanjavur College Hospital, through its report dated 05.07.2019 had remarked that the candidate has 'defective colour vision' and since no visual norms for colour vision was specified, his fitness to exercise his duties cannot be certified. 3. Thereafter, the petitioner was extended with an opportunity of personal hearing before the Chief Engineer (Personal), wherein he had submitted that he was not aware of his defectiveness in colour vision until the test was performed and that he was not wearing spectacles prior to that. Not being satisfied to the reply, the petitioner was referred to a Committee of four members, which further subjected the petitioner to appear before the Regional Institute of Ophthalmologist and Government Ophthalmic Hospital, Egmore, Chennai 600 008 to ascertain his colour vision. For the third time, the Regional Medical Board at Chennai had opined that both the left and right eyes of the petitioner were 'colour vision defective'. For the third time, the Regional Medical Board at Chennai had opined that both the left and right eyes of the petitioner were 'colour vision defective'. In this background, the respondents had relied upon the various work norms to the post of an Assistant Engineer(Electrical) and the nature of his duties and had observed that the responsibility attached to the post of an Assistant Engineer(Electrical) requires him to differentiate the colour terminals to ensure correct supply of power, safety of co-workers, safety of public and safety of himself and since he was diagnosed with a colour vision defectiveness, he was rendered as 'unfit' for serving as an Assistant Engineer(Electrical), through the impugned order, dated 14.05.2020. The rejection order is put under challenge in the present writ petition. 4. The learned counsel for the petitioner would submit that the petitioner's vision is perfect to lead a normal life and that he was neither aware of the defective in colour vision until the tests were performed by the respondents nor did he use the assistance of the spectacles for a normal vision and therefore, there was no impediment for him to perform the duties of an Assistant Engineer. It is his further submission that since there was no norms fixed to invalidate him in the medical tests, insofar as the percentage of colour vision defectiveness is concerned, the respondents are not justified in rejecting his candidature. 5. On the other hand, the learned standing counsel for the respondent/ Tamil Nadu Generation and Distribution Corporation (hereinafter referred to as the TANGEDCO) would place reliance on the various duties, functions and responsibilities for the post of an Assistant Engineer(Electrical) and submitted that since the defect established in the medical report would hamper the work of an Assistant Engineer(Electrical), there is no infirmity in the findings of the respondents in the rejection order. However, the learned standing counsel fairly admitted that there are no norms fixed by TANGEDCO insofar as disqualification of a candidate on the percentage of a colour vision defectiveness is concerned. 6. I have given careful considerations to the submission made by the respective counsels. It is not in dispute that the petitioner herein is a successful candidate in the selection for the post of Assistant Engineer (Electrical) on merit basis. 6. I have given careful considerations to the submission made by the respective counsels. It is not in dispute that the petitioner herein is a successful candidate in the selection for the post of Assistant Engineer (Electrical) on merit basis. The only impediment pointed out by the respondents is that he suffers from colour vision defectiveness and therefore, is not fit for performing the ordinary duties attached to the post of an Assistant Engineer (Electrical). When the petitioner was subjected to medical examination before the Ophthalmological Department of three Medical Boards, both his eyes were detected of being defective in colour vision. The respondents had twice sought for the opinion of the medical experts with regard to the petitioner's fitness to undertake the job of an Assistant Engineer (Electrical) and had supplied with supporting materials connected with the duties, functions and responsibilities for the post of Assistant Engineer, to which both the Medical Boards of Thanjavur Medical College and the Regional Institute of Ophthalmology, Chennai had declined to opine on the petitioner's fitness, since no visual norms for colour vision was specified. The respondents also admit that there are no visual norms for colour vision for the purpose of certifying the fitness of a candidate. 7. The Superintending Engineer, in his letter dated 15.04.2017, has assumed that the petitioner had '"colour blindness"' which, was not backed with any medical report. Likewise, the Chief Engineer(Personal), in the impugned order of rejection has also termed the petitioner's eye condition as "colour blindness". On the contrary, the medical experts attached to the Ophthalmological Department of the two Hospitals referred above, were clearly of the view that there was only a 'defective colour vision' and not "colour blindness". There is a huge difference between '"colour blindness"' and ' defective colour vision'. In the case of defective colour vision, the person with such defect could perform his normal routine life, if the defectiveness is minimal and probably, if the defectiveness was to be maximum, may be such candidate may have some inconvenience in his routine vision. 8. Admittedly, such norms have not been prescribed in the notification dated 28.12.2015 calling for applications to the post of Assistant Engineer (Electrical), nor does the recruitment regulations of TANGEDCO prescribe these norms. 8. Admittedly, such norms have not been prescribed in the notification dated 28.12.2015 calling for applications to the post of Assistant Engineer (Electrical), nor does the recruitment regulations of TANGEDCO prescribe these norms. While the medical experts have not certified the fitness of the petitioner's colour vision, the respondents seem to have unilaterally come to a conclusion that the defectiveness in 'colour vision', opined by the medical expert, would be to such a percentage as to hamper the regular duties of an Assistant Engineer (Electrical). Such a decision is not based on intelligible differentia. No reliance has been placed on expert reports or any other material for the respondents to arrive at such a conclusion. 9. The impugned order seems to place much reliance on the duties, responsibilities and functions for the post of an Assistant Engineer (Electrical). In order to ascertain as to whether a candidate holding the post would be disentitled or unfit to perform such duties, functions or responsibilities, the determination requires to be made on the basis of some materials supported by the reports of medical experts. In the absence of such materials or medical report and merely relying upon the duties, functions and responsibilities for the post of Assistant Engineer (Electrical), would be illogical and baseless and hence, such reasoning rendering the petitioner 'unfit', could be termed as 'arbitrary'. 10. As such, the impugned order itself cannot be sustained and consequently, the appointment order requires to be revived. It would not be out of place to mention here that, in case TANGEDCO is of the view that they require to re-exercise the medical tests on the petitioner with regard to his colour vision is concerned, the same can always be exercised, after framing of norms with regard to such colour vision for their employees. However, such norms should be based on the basis of the opinion of the medical experts vis-a-vis, the duties, functions and responsibilities of any post. 11. In the light of the above observations, the impugned order dated 14.05.2020 on the file of the second respondent is quashed. However, such norms should be based on the basis of the opinion of the medical experts vis-a-vis, the duties, functions and responsibilities of any post. 11. In the light of the above observations, the impugned order dated 14.05.2020 on the file of the second respondent is quashed. Consequently, there shall be a direction to the second respondent herein to issue fresh posting orders, appointing the petitioner to the post of Assistant Engineer (Electrical), with effect from 31.03.2017, which is the date of his original appointment, as expeditiously as possible, in any event, within a period of four weeks from the date of receipt of a copy of this order. 12. The Writ Petition stands allowed accordingly. However, there shall be no order as to costs. Consequently, connected W.M.P.(MD) No. 12724 of 2020 is closed.