I'm a tad confused here, and perhaps it's because of language or cultural differences?
are we talking about design engineers, as in the people who work mostly with theory and mathematics (most of the electrical engineers I knew at school were in this category). I agree vision would be a benefit to this type of work, but hardly a requirement... mental abilities are important here, not physical abilities.
or are we talking about electrician / technicians, who may also be engineers, that are working in the field, repairing stuff or assembling it in a factory? I can see physical abilities such as vision and dexterity being the strong requirements for this type of work, with mental abilities being secondary (although still important).