To provide an optical lens unit which is advantageous for obtaining parallel rays of light inside a curved light-transmitting body, such as a tubular lens, while holding down the price and advantageous also for forming a curved light-transmitting body of a very hard material such as sapphire, etc., and to provide a visualization apparatus and a method of designing a correcting lens of the optical lens unit. 価格を抑えつつ、管状レンズなどの曲成透光体の内側において平行光を得るの有利であり、曲成透光体をサファイア等のような極めて硬い素材で形成するのに有利な光学レンズ装置、可視化装置、光学レンズ装置の補正レンズの設計方法を提供する。 - 特許庁