Hello and welcome to the Zero to Finals podcast. My name is Tom and in this episode I'm going to be

going through Cataracts. And you can find written notes on this topic at zero tofinals.com

slash cataracts or in the ophthalmology section of the zero to finals medicine book.

So let's get straight into it.

Cateracts occur where the lens in the eye becomes cloudy and opaque.

And this causes a reduced visual acuity by reducing the amount of light that can enter through

the eye and through the lens to get to the retina.

The job of the lens in the eye is to focus light that's coming into the eye onto the retina

at the back of the eye where that light is sensed and the brain is able to create an image

of what's seen on the eye. The lens is held in place by suspensory ligaments, which are attached to something

called the ciliary body, and the ciliary body contracts and relaxes in order to focus the lens,

but changes the shape of the lens in order to properly focus the light onto the retina. When the ciliary

body contracts, it actually releases tension on the

suspensory ligament, and this causes the lens to thicken. And when the ciliary body relaxes,

it increases the tension on the suspensory ligaments, and the lens becomes more narrow. The lens is

nourished by the surrounding fluid, and it doesn't have a blood supply.

And throughout life, the lens continues to grow and develop.

Most cataracts develop over years in the presence of several risk factors.

Congenital cataracts occur before birth and a screen for using the red reflex during the neonatal

examination.

So they usually picked up early.

But usually cataracts are associated with older age and several risk factors.

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