Final answer:
The power of the tear layer is determined by the difference in refractive indices between the tear layer and the cornea.
Step-by-step explanation:
The tear lens, formed by the posterior surface of the RGO lens and the anterior surface of the cornea, contributes to the power of the eye. However, the power of the tear layer is not determined by the tear lens. Instead, the power of the tear layer is determined by the difference in refractive indices between the tear layer and the cornea. This difference in refractive indices causes the rays of light to bend, allowing for proper image formation on the retina.