The lens is a transparent and elastic structure located just behind the cornea in the eye, functioning like a lens.

It acts like a camera lens, refracting light to focus it onto the retina.
The lens measures approximately 9 mm in diameter and about 4 mm in thickness.

The main characteristics of the lens are as follows:
・Transparency: Allows light to pass through
・Elasticity: Soft when young, changes shape to adjust focus
・Avascular: Nutrients are supplied via a fluid called aqueous humor
・Protein-rich: Mainly composed of a special protein called crystallin

The lens changes shape via a muscle called the ciliary muscle to adjust focus.
・When viewing near objects → ciliary muscle contracts → lens thickens → refractive power increases
・When viewing distant objects → ciliary muscle relaxes → lens thins → refractive power decreases

However, as we age, the lens loses its elasticity, making it difficult to focus on nearby objects.This condition is commonly known as presbyopia.

With aging, the proteins that make up the lens deteriorate, causing it to become cloudy, resulting in blurry vision or decreased eyesight.
These symptoms are referred to as cataracts.

Cataracts progress gradually and are often asymptomatic in the early stages, so by the time symptoms appear, the condition may already be advanced.
Once cataracts develop, eye drops may slightly delay progression, but the lens cannot return to its original state.
Surgery is the primary treatment for cataracts.
Cataract surgery involves removing the cloudy lens and inserting an intraocular lens.
For more about cataracts, please refer to our previous publication:‘Eye Diseases – Cataract’.