Just wondered how critical this is to customers in general.
The AR coating is presumably designed so that the reflected colour appears correct when viewed at normal incidence (90 degrees from the surface). Although small angles of deviation make little difference, this colour will change for larger viewing angles. The curvature of larger diameter lenses means that light entering the eye from the outer zones has been reflected through a large angle. The spectrum of the edge coating of a curved lens is likely to show a shift anyway because of the mechanics of the vacuum deposition process.
What I am saying is, that despite the best efforts of coating labs, it is very difficult to achieve a total uniformity of product. A lens may still have good antireflective properties even though the relex colour is poor.
What I would like to know is how much this bothers the end users. Clearly, the reflex colours of left and right lenses should match, and the front and rear reflex colours of each lens should also be comparable. Apart from this, are many lenses rejected for reasons of colour? How do stores make the judgement of whether or not the coating is acceptable? Do they look at reflections from lighting at normal incidence, or is the whole thing more subjective, and seen as the end user would experience it?
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