Optical devices with switchable optical properties have attracted great interest in recent years because of their extensive engineering applications. The dynamic tuning of optical properties can be triggered by various types of external stimuli. In this work, a mechanically induced elastomeric optical transmittance modulator is reported. The design is composed of poly(dimethylsiloxane), a silicone-based rubber transparent at visible wavelengths, with gold nanofilms deposited on the surface. The influence of geometric parameters on the total transmittance is studied utilizing the Rigorous Coupled Wave Analysis model. Taking advantage of the excellent stretching capacity of the elastomer, reversible modulation of both normal and total transmittance is achieved. A 42% rise in the total transmittance is realized under a strain of 80%. Cycle testing illustrates stable structural integrity and optical performance even after repeated strain cycles. This elastomeric optical transmittance modulator opens avenues for practical applications due to its simple design and facile tunability.