If intended to ask about eye contact duration in professional settings, maintaining eye contact for 3 to 5 seconds is considered appropriate in many Western cultures.
The phrase 'professional eye elevation' is not a common term in any field, and there seems to be a misunderstanding or typo in the question, as it does not pertain to a standard metric or practice within medicine, ophthalmology, or any related health sciences.
However, if interpreted as 'how many seconds should a professional hold eye contact', it is a question related to social communication norms rather than medical science.
The appropriate duration for eye contact can vary widely depending on cultural context, social situation, and personal comfort. In many professional settings in Western cultures, maintaining eye contact for 3 to 5 seconds is considered appropriate, but this can vary.