Other things being equal, perhaps we might. But of course they're not equal. Our social morality -- the morality we live by -- is 'speciesist' in the sense that human beings -- whatever their mental or physical capacities -- are considered to be due special protection. If we were to seek to remove that protection, chances are that it would probably degrade our ethical sensitivities to the point that things went overall worse for non-human animals than they do at present. What we should be asking, rather than your question, is: Why should we continue testing drugs and cosmetics on non-humans to the extent we do, when we wouldn't dream of carrying out such testing on human beings with similar capacities?

I assume we're imagining that the doctor knows that the patient hasn't herself reported her optical problems. I suppose the first thing to try would be asking the patient to do so. Now imagine that the patient refuses, or that the doctor has reason to suspect that the patient won't make a report. The first issue is whether the law requires the doctor to inform the authorities. If it does, then it seems to me pretty clear that she should do so. If the law doesn't require this, then the doctor may be subject to legal, or professional, obligations of confidentiality. If those are absent too, then I'm inclined to think she should go ahead and make the report. It might be said that it would damage the relationship of trust between her and her patient, and I guess that is more than likely if the patient's driving licence is revoked! But that seems a price worth paying. Nor do I think it would do much if any harm to the reputation of the doctor, or doctors in general, if it became known that the doctor had...