An extendable and retractable eyewear telescoping retaining strap assembly consisting of an outer tubular strap member and an inner strap member slidably disposed within the tubular member. Means are provided to secure the inner strap within the outer strap in the retracted position and to prevent the separation of the two straps when the inner strap is in the extended position. The assembly is attachable to the temple of an eyewear frame either by attaching the outer tubular strap to the temple or by attaching the inner strap to an additional retaining strap disposed within the temple. Each strap of the assembly is flexible and either longitudinally stretchable or inelastic to provide for different modes of use.