A cataract is a cloudy natural lens within the eyes.
In childhood and adolescence, most people have clear, flexible lenses within their eyes to allow them to see well. The clarity of the lens offers clear, unobstructed vision at the distance; the flexibility of the lens allows it to dynamically change its focus (called ‘accommodation’) to see near objects as well.
As we age, the lens becomes hard and cloudy. When the lens hardens over time, it loses its ability to dynamically changes its shape (accommodate), which manifests with patients needing reading glasses, bifocals or progressive glasses to see near objects. This condition is called ‘presbyopia’. This typically occurs around age 40 for most people.
When the lens becomes cloudy, it begins to obstruct the vision and reduces the clarity of one’s vision. The cloudy lens is called a ‘cataract’. As we continue to age, the cataract becomes progressively cloudier, which in turn causes the vision to worsen. In the early stages of cataracts, this reduction in vision can be treated with updating one’s glasses prescription. At a certain point, though, the cataract is too cloudy to be corrected with glasses, and cataract surgery is recommended to improve the vision.
Cataracts are a normal age-related change within the eye. In some cases, cataracts can be caused by other factors, including trauma, certain systemic diseases, or medications.
The intraocular lens is the replacement lens placed inside the eye after the cataract is removed. This lens is typically made of acrylic or other synthetic polymer; these materials are well tolerated in the eye and last indefinitely.
The simplest intraocular lens (typically covered by insurance) is called a ‘monofocal’ lens, which is a rigid clear lens. These lenses gives good clarity of vision at a single plane of focus. One limitation of them is that they typically worsen presbyopia symptoms; thus, glasses are needed to achieve good vision at most distances.
In recent years, advances in optics technology have yielded newer refractive intraocular lenses which can be reduce one’s dependence on spectacles after cataract surgery. They do so by treating astigmatism and/or presbyopia. These lenses are well tolerated and can be an excellent option for patients looking to reduce their need to wear glasses after cataract surgery.
For most patients, we recommend cataract surgery once cataracts begin causing vision issues that begin interfering with one’s day-to-day activities despite spectacle correction. This may include difficulty with driving (especially at night), watching TV, reading, cooking or even reading the clock. The symptoms one may experience depends on the severity of cataracts as well as on one’s daily activities; for that reason, the decision on timing of cataract surgery varies from person to person depending on your needs. For reference, the typical age for cataract surgery in the US is late 60s to early 70s.
In some cases, cataract can also cause health issues within the eyes, including some types of glaucoma and inflammation. In these cases, cataract surgery may be recommended to help treat those conditions. Consult your surgeon if this is the case for you.
