Also answering the related question: why did they feel the need to wear clothes?
The account of Adam and Eve eating the fruit in Scripture states:
So when the woman saw that the tree was good for food, that it was pleasant to the eyes, and a tree desirable to make one wise, she took of its fruit and ate. She also gave to her husband with her, and he ate. Then the eyes of both of them were opened, and they knew that they were naked; and they sewed fig leaves together and made themselves coverings. (Genesis 3:6–7)
There are a host of possibilities why Eve’s eyes were not opened until Adam ate. The obvious ones are:
They ate so close to the same time that the time difference was negligible.
The effects were not immediate, but took a short amount of time (perhaps a matter of seconds or minutes) for them to feel the shame and for their eyes to be opened.
Other answers have some potential as well. Consider:
The original command not to eat was given to Adam, so there may have been no bearing on Eve when she ate. In other words, just because she ate, it was meaningless. (However, I would lean against this view since Eve pointed out to the serpent in Genesis 3:2 that God’s command encompassed her as well.)
Adam was responsible for his wife. In fact, the woman was created for the man (1 Corinthians 11:9), and so the created order began with Adam (which Satan through the serpent refused to acknowledge when he approached Eve first). So Adam would have had to fall for their eyes to be opened. Simply put, Adam was the one responsible, even for his wife’s actions.
Both had dominion, so both Adam and Eve had to fall for the change to occur. This perspective is based on Genesis 1:26–28, where Adam and Eve were given dominion together. In other words, for the entire dominion of man to fall, both had to sin.
Think of it conversely. If Adam had eaten first, would the same thing have happened? In the shared-dominion perspective, the answer would be yes. If Adam had eaten first nothing would have appeared to happen, but when Eve would have eaten, then both had sinned and the entire dominion would fall.)
With this view, if Eve had eaten and Adam had not, then the dominion would not have fallen, and only Eve would have been punished and died. Of course, there are really no “what ifs,” so we shouldn’t get caught up in too much of this type of thinking. Notice that the repercussion of Eve’s sin affected her and subsequently all women since that original sin (Genesis 3:16). But notice Adam’s punishment in Genesis 3:17–19—the ground was cursed (i.e. the whole of the dominion). The apostle Paul revealed the extent of this curse in Romans 8:20–22 as being the whole of creation, which is why we need a new heavens and a new earth.
In fact, this view could be coupled with the previous view (number 4). Both Adam and Eve had dominion, but Adam was ultimately the responsible party. Consider Romans 5:12 in regard to these last two viewpoints:
Therefore, just as through one man sin entered the world, and death through sin, and thus death spread to all men, because all sinned. (Romans 5:12)
Naturally, these last two views (4 and 5) may be reading too much into the account, but it is worth considering in light of Scripture. After all, Adam received the blame for sin’s entrance, so he was the responsible party. However, the answer may simply be that Adam and Eve ate at practically the same time, or the effect may have had a slight delay (seconds to minutes). But when looking closely at this passage, one can’t help but discuss what exactly Scripture means by, “their eyes were opened”—let’s evaluate this in the next section.
Why Did They Feel the Need to Wear Clothes?
Here are a couple passages in regard to Adam and Eve having their eyes opened and realizing their nakedness:
And they were both naked, the man and his wife, and were not ashamed. (Genesis 2:25)
Then the eyes of both of them were opened, and they knew that they were naked; and they sewed fig leaves together and made themselves coverings. (Genesis 3:7)
When Adam and Eve sinned the Bible says their eyes were opened. The very next statement says they realized they were naked—and then further, they decided to make clothes.
So their sin affected the way Adam and Eve perceived things (i.e., their eyes were opened). In fact, the shame they now felt was due to sinful nature, because they no longer perceived things in a perfect fashion. Hence, they viewed that their nakedness should be covered.
By wearing clothes, cultures and religions all over the world are confirming the Bible’s account is true.
Note that nakedness was not a sin, but a fallen perception of nakedness and the associated shame was included in the sorrows and mental anguish they now felt. Even today, nakedness is bonded with shame, as people the world over wear clothes. In fact, this doctrine of clothing that comes out of a literal rendering of Genesis reveals that, by wearing clothes, cultures and religions all over the world are confirming the Bible’s account is true.
For example, an atheistic worldview holds that people evolved from animals and are animals, so why wear clothes? Some would say that we need clothes to stay warm, but some climates do not require any clothing for that purpose. Animals don’t put on clothes. Consider other religions like Hinduism, where nothing is ultimately reality. Why wear clothes? (Islam borrows from the Bible, etc.) Please do not get me wrong, I am not asking people from these other religions to stop wearing clothes because it is a Judeo-Christian doctrine. In fact, we appreciate that they adhere to this doctrine.
What we would ask is that these people who have been taught their respective religions consider the meaning of wearing clothes and how that goes back biblically to our mutual ancestors, Adam and Eve, and sin. Such things show the validity of God’s Word, pointing toward Christ who conquered sin on our behalf and now offers the free gift of salvation to all who believe (see What Does It Mean to Be “Saved”?).