The SDK does not include any data streams that provide pre-computed indicators of Visual Evoked Potentials (VEP). The only visually-related path available right now is the /dsp/blink path. You can definitely explore detecting VEPs using the raw data from Muse, though.
You’re right that the occipital locations are very commonly used for VEP studies because of their proximity to the visual cortex. However, the forehead locations also are known to display certain components of VEP waveforms, as mentioned in this paper, for instance: http://bit.ly/1x3R3Wa
To learn more about how VEPs are typically measured and analyzed I’d also recommend looking at the VEP Standard (2004): http://bit.ly/1t8VuKe
Both the ear and forehead electrodes pick up useful information about eye movement and position. Since the eye itself forms a dipole (called the corneoretinal potential) that runs from the front to the back of the head, if it moves or changes (say because you are looking around or blinking or refocusing), the potential that appears to the electrodes will change. There are lots of papers and resources on this stuff - here’s one good example: http://bit.ly/10SY0i9