~につれて (as, in proportion to)

As the days went by, the leaves turned to autumn colours.

As civilization advances, poetry almost inevitably declines.

She grew increasingly beautiful as she got older.

As the conversation progressed, his eloquence grew sharper and sharper.

As I've gotten older, I've gradually been becoming farsighted.

Many people become unable to take care of themselves as they age.

As the weather got colder, his condition kept getting worse.

It got colder as the night wore on.

As she grew, she gradually became more beautiful.

As she grew up, she became more and more beautiful.

The skin became harder as it dried.