What is the word for "fear of the sun?"

Heliophobia is a psychological condition which is an actual fear of the sun or sunlight. Photophobia is physical condition for which patients must avoid being in the sun or bright light. People with heliophobia may have had some experience that makes them terrified of being in the sun-- like having a severe sunburn or witnessing someone suffer skin cancer. Sometimes the phobia is for no reasonable reason.

Photophobic persons, on the other hand, must avoid or limit sun exposure. They may be sensitive to light, sun, or glare as those with certain conditions as albinism, cataracts, medical conditions, or medicinal side effects. We think of the suffix "phobia" as meaning "fear of" but in the the case of photophobia a physical condition is present; not necessarily a fear.

Now that you know, would you describe your vampire friends as heliophobic or photophobic?