Definition
In the absence of a cataract, the crystalline lens (a curved lens located inside the front part of the eye) is transparent.
The appearance of a cataract reflects the loss of transparency of the crystalline lens, which therefore transmits images less well. This cataract blurs the perception of images and colors.
It can be partial or total.
Types and causes
Cataracts are differentiated by their location: capsular and subcapsular, cortical or nuclear, equatorial or polar. They are also differentiated by their causes:
- Age: In the vast majority of cases, cataracts have no particular cause, other than age. They can appear after the age of 70 in a very gradual manner. However, there are certain factors that can aggravate and accelerate the disease, such as: exposure to ultraviolet rays, smoking, alcoholism, diabetes and certain treatments (prolonged corticosteroid therapy) and metabolic diseases.
- congenital cataract, most often of hereditary origin: it appears in very young children. The surgical intervention will be more or less rapid depending on the opacity of the lens.
- traumatic cataract: this often appears quickly but sometimes later after an impact on the eye.
- cataract secondary to serious eye infections: such as old uveitis, retinal detachment.
And mainly treated adult cataracts.
Signs
The most common signs of cataracts are: visual fog, haze, decreased visual acuity, floaters, glare, photophobia.
Opacification of the lens usually occurs gradually and can last for several years. Sometimes it occurs more quickly.
Any other signs such as pain, dizziness, headaches are not directly attributable to cataracts.
