Based on the community answers, Apple appears to use outside manufacturers for iPhone camera lens modules, while the optical design may be developed in-house.

Suppliers named in reports include Largan Precision, Genius Electronic Optical, and Kantatsu. Those companies are optical manufacturers that build components or modules for Apple. There’s no evidence in the provided answers that Apple brands iPhone lenses through companies like Zeiss or Canon in the way some phone makers have used co-branding.

One answer also states that the iPhone lenses are designed in-house and describes them as multi-element, strongly aspherical designs. So the most accurate summary here is: Apple likely specifies or designs the lens system, but manufacturing is outsourced to specialist optics suppliers.

That arrangement is common in consumer electronics: a company controls the product design and performance targets, while specialized suppliers fabricate the optics and assemble modules.