What are the parts of speech of the words in 车外的阳光格外的刺眼, and why is this 的 correct? 车外的阳光格外的刺眼.

That's a complete sentence. I've got troubles understanding what parts of speech are. According to my dictionaries:
阳光 - sunshine,
格外 - especially,
刺眼 - to dazzle.
So the sentence would mean &quot;The sunshine outside the bus was extraordinarily dazzling&quot;.
But... There's the second 的 in this sentence (阳光格外的刺眼). And objects which go after 的 are nouns (from what I know). So 刺眼 turns to be a noun? If so, where's the verb in this sentence? I really don't understand this 的. I'd gladly put 地 instead.
Edit:
This is 100% clear: 车外的阳光. The unclear 的 is here: 阳光格外的刺眼.
车外： Object + related location/position = place term, n.
的： Aux. term to turn n. into descriptive, usually in possession/belonging relation; or habitually added after multi-character adj. (single character adj. usually is optional with 的)
阳光： n. subject of the sentence
格外： itself is adv. no need to add any aux term.  月亮格外明亮/汉语格外难学
的： Double mistake - no need at all, or even if you want to put aux term, it must be 地
刺： v. as predicate.，literally means &quot;to sting&quot;
眼： n. as object.

Perfect:  车外的阳光格外刺眼。
Not so good:  车外的阳光格外地刺眼。