1stQ is a German ophthalmic technology company based in Germany, specializing in intraocular lens (IOL) solutions for lens surgery. The company is particularly known for its advanced AddOn® supplementary IOL technology, which provides surgeons with a flexible and effective option to fine-tune refractive outcomes in pseudophakic patients. Its patented AddOn® lenses allow additional correction of residual refractive errors—including astigmatism and presbyopia—while ensuring stable positioning and offering the advantage of reversible implantation when needed.