Cataract surgery involves extracting the content of the opacified crystalline lens using ultrasounds and replacing it with a custom-made intraocular lens (IOL).

With regard to incipient cataracts, palliative measures can be taken such as the use of sunglasses to avoid glare or prescription glasses if you've experienced a change in refraction. But the definitive treatment for cataracts is still surgery. 

Cataracts may appear at any age. They may even be congenital, although in general, cataracts generally appear during old age. As soon as the patient starts to notice a loss of visual acuity and is no longer comfortable, cataract surgery can be proposed and performed.