What is intraocular pressure or eye pressure?
Intraocular pressure (IOP), or eye pressure, measures the pressure or force inside the eyeball.
Read article ↗WHAT YOU NEED TO KNOW
- The expression “a dirty intraocular lens” is sometimes used to describe clouding of the back of the capsular bag in which the lens was implanted during lens surgery.
- To understand this condition, it helps first to clarify a few anatomical concepts.
- The crystalline lens is the natural lens inside the eye that helps us focus on objects.
The expression “a dirty intraocular lens” is sometimes used to describe clouding of the back of the capsular bag in which the lens was implanted during lens surgery.
To understand this condition, it helps first to clarify a few anatomical concepts.
The crystalline lens is the natural lens inside the eye that helps us focus on objects. It lies centrally, separating the front and back parts of the eye.
Anatomically, the natural lens consists of flexible, protein-rich material enclosed in a capsule. Equatorial fibres (zonules) connect this capsule to the ciliary muscle, whose action allows young people to change the lens's curvature and focus sharply on near objects.
When lens surgery is indicated for cataract, a high refractive error and/or presbyopia, the inner contents are broken up and aspirated, while the surrounding capsular bag should remain intact.
After an intraocular lens has been implanted, the capsular bag can therefore still undergo fibrosis and clouding that may significantly reduce visual quality.
Capsular opacification
Posterior capsule opacification is treated by a capsulotomy in a single outpatient YAG (Yttrium Aluminum Garnet) laser session, with rapid visual recovery.
This information does not replace an individual medical assessment. Follow the advice of the team looking after you.
Dr. Nuno Lopes · Patient information
Editorial presentation updated on 27 October 2026. Your team's individual instructions take priority.
