When light waves first enter the eye, they first pass through this transparent layer where they are refracted

The first thing they pass through is the 'cornea' . . . that's the curved 'bubble' in front
of your eye that covers the colored part.

Refraction happens at several levels of the eye, but the cornea is the first.

stands for electromotive force and it is measured in volts. despite its name, it is not actually the force in the sense of being a "pushing" or "pulling" (not measured in newtons).an equation that relates emf,  ℰ,  to a battery's terminal voltage, v, current, i, and internal resistance, r, is    ℰ = v + irin this case, the emf can be interpreted as a voltage—a difference in electric potential.i would not say that it would be considered an energy. if emf can be defined as the energy/work per a unit charge from a battery or other electric source, then it is not strictly energy.