Why does presbyopia make it hard to see things up close even when you can see far away?

Recently, I find it hard to see my smartphone or books unless I hold them a bit further away.
By the evening, things up close tend to get blurry, and my eyes feel tired easily.

“Could this be presbyopia... no, I should still be fine.”

Have you ever thought that?

In the articles up to the one before last,
we looked at the foundation for this topic.
This time, we will finally connect that to presbyopia.
If you haven't read them yet, please check them out as well ⬇️

So,
what is the relationship between presbyopia and that “accommodation”?

Presbyopia is a change where the ability to see things up close weakens.

First, let's look at the most important point.

Presbyopia is a condition where the power of “accommodation” used when looking at things up close
gradually weakens with age.

So, why does the situation where “you can see far away but it is hard to see up close”
happen?

When looking at things far away,
your eyes can focus with almost no accommodation.

On the other hand, when looking at things up close,
your eyes need to accommodate to focus.

In other words, as the power to accommodate weakens,
even if you can see far away, text or small objects up close
become prone to blurring.

“I can see far away, so it’s not presbyopia” is not necessarily true.
You need to think of your distance vision and your ability to focus up close
separately.

The main reason why presbyopia makes it hard to see up close

So,
why does it become harder to accommodate with age?

A major factor involved is
the “crystalline lens” inside the eye.

The crystalline lens is mainly made of transparent protein.

As the properties of that protein gradually change with age,

the crystalline lens loses its elasticity and becomes harder.

When the crystalline lens becomes hard,
it becomes difficult for it to change shape when looking at things up close.

Therefore, even if you try to focus on something up close,
it becomes harder to do so than when you were young.

This is the main reason why presbyopia makes it difficult to see things up close.

Accommodative power does not disappear suddenly one day.

When you are in your teens,
you have the power to focus on things quite close up.

From there, your accommodative power gradually decreases with age,
and the distance at which you can focus on nearby objects
also gradually moves further away.

For example, for a person with normal vision,
at around age 10, they can focus on objects at a distance of about 7 cm from their eyes up to that point.

That distance becomes about 22 cm from the eyes at around age 40,
and about 40 cm from the eyes at around age 50, so the closest distance at which you can focus
gradually moves further away.

In other words,
presbyopia is not so much about "suddenly not being able to see up close one day," but rather
a change in accommodative power that has been ongoing since you were young,
which becomes easier to notice in your daily life.

Note: There are individual differences in accommodative power and how things look up close.
Also, how you perceive it changes depending on your refractive state, such as nearsightedness, farsightedness, or astigmatism.

The reason for difficulty in seeing is different from that of cataracts

Here, I will briefly clarify the difference from cataracts.

Both presbyopia and cataracts involve the "crystalline lens."

Both share a common underlying process where
the proteins in the crystalline lens change with age.

However,
the reason why these changes lead to difficulty in seeing is slightly different.

In cataracts,
the transparency of the lens decreases due to changes in the lens proteins,
and the cloudiness affects your vision.

It is easy to understand if you think of presbyopia as a change in "difficulty focusing," and
cataracts as a change in "difficulty seeing due to cloudiness."

Difficulty in seeing manifests slightly differently depending on nearsightedness and farsightedness

Presbyopia occurs in both nearsighted and farsighted people.

However, depending on the original state of your eyes,
the way (and timing) in which difficulty seeing up close appears will vary slightly.

What is important here is
that the "starting point of accommodation" differs from person to person,
that is all.

Farsighted people may be using accommodation
even when looking at things far away.

Therefore,
as your accommodative power weakens with age,
you may find it easier to feel difficulty or fatigue when looking at things up close
from a relatively early stage.

On the other hand, people with nearsightedness
have eyes that are naturally better at focusing on things up close.

Because of this, when they take off their glasses or contact lenses,
they may find it easier to see things up close.

You can read more about how farsightedness and nearsightedness work here⤵️
Reading this as well will make it easier to understand
the difference in the "starting point of accommodation."

Because of this difference,
people sometimes think that "nearsighted people are less likely to get presbyopia."

But in reality, whether you are nearsighted or farsighted,
your ability to accommodate changes with age.

It is just that the timing and the way you feel the difficulty in seeing differ,
but presbyopia itself is a change that happens to everyone.

*The cause of difficulty in seeing
is not always just presbyopia.
Don't just assume it's probably presbyopia;
if you are concerned, it is important to consult an ophthalmologist
and check the current condition of your eyes.

Let's start by understanding the changes in how you see.

Presbyopia is an age-related change that happens to everyone.

When you start finding it hard to see things up close,
there is no need to give up and say, "I'm just getting old."

First, understand what is changing inside your eyes.
And it is important to be aware of how you are seeing.

You can see far away, but it is hard to see up close.
Rather than your eyes suddenly getting worse,
this might be a sign that your ability to focus on things up close
has been changing little by little.

If there is anything you don't understand,

"Is it okay to ask something like this?"

Questions like that are perfectly fine.

Please feel free to ask via the Marshmallow link below👇️

Any question, no matter how small, is fine.

I will kindly answer as much as I can.