<p>A curable composition which comprises: a bisphenol A epoxy compound (A-1) modified with a carboxy-terminated butadiene/nitrile rubber and/or an epoxidized polybutadiene compound (A-2); and a cationically polymerizable compound (B) other than the compounds (A-1) and (A-2). The curable composition is characterized by giving a cured object which has a refractive index as measured at 25°C and 589 nm of 1.40-1.60. This curable composition enables an optical device to be kept bonded over long without suffering any trouble such as separation even in a high-temperature environment or high-temperature high-humidity environment. Also provided is anoptical device made with the curable composition.</p>
