An intraocular lens power determination apparatus for determining a highly precise IOL power, the apparatus including: an anterior segment imaging device for obtaining a cross-sectional image of an anterior segment by detecting reflection from the anterior segment of an examinees eye and a power calculation unit obtaining an offset distance from a front surface of a lens to a point of contact of a Zinns zonule with the lens based on the anterior segment cross-sectional image obtained by the anterior segment imaging device and calculating a prospective postoperative anterior chamber depth by adding the offset distance to an anterior chamber depth of an eye so that the IOL power is calculated by using the prospective postoperative anterior chamber depth.
