Thank you for your question.Back in the 70's, various studies were done measuring all types of relationships in the human's face called anthropometric measurements. However, this was done mostly on caucasians. The results of those studies were as you indicated in your question: the inter-nostril width should be approximately the same as the inter-canthal (inner eye corner) distance.Now in my practice in Toronto, I use those guidelines with 'moderation'; I ALWAYS account for the ethnicity of my varied patients' practice (Toronto is very multicultural, as you know), their wishes, etc. More importantly, I aim for harmony between the various components of one's face - which I call "artistry".One must also take into considerations that the inter-canthal distance may be shorter or longer than the average person. So yes, there is variation also for the inter-canthal distance. This can also be modified, although it is a much more complex procedure.Hope this helps! Best regards,Dr. Marc DuPere, Toronto Aesthetic Plastic Surgeon