The lens is the transparent part of the eye that sits behind the iris. It helps focus images or light on the retina, changing the images into nerve impulses and sending them to the brain. Under normal conditions, the lens is clear, allowing it to send sharp and clear images to the retina.
When somebody develops a cataract, the lens becomes cloudy, rendering the image blurry. Cataracts are the primary cause of blindness around the world. According to Prevent Blindness America (PBA), there are more cases of cataracts globally than there are cases of glaucoma, diabetic retinopathy and macular degeneration put together. Cataracts also constitute the most common cause of blindness in people over 40. The PBA reports that 22 million Americans in this age group have cataracts, and they estimate that number will increase to 30 million by 2020.
Types of cataracts
Cataracts can be categorized by the part of the lens in which they first develop. The different types of cataracts include the following:
- A nuclear cataract develops in the nucleus or center of the lens. This type of cataract is usually seen in older patients.
- A cortical cataract originates in the lens cortex that surrounds the nucleus. The cataract takes the form of white, wedge-shaped spots that work their way to the center of the lens. Cortical cataracts can look like the spokes of a wheel.
- A subcapsular cataract is found at the back of the lens. They are most common in people with diabetes and those who take high amounts of steroid medications.
Cataracts can also be classed by their cause:
- Secondary cataracts are caused by another disease or health problem. They can be caused by other eye disorders like glaucoma or diseases like diabetes.
- Traumatic cataracts are caused by eye injuries, and they may take years to develop after the original injury.
- Congenital cataracts are evident at or shortly after birth.
- Radiation cataracts are caused by exposure to certain types of radiation.
What are the symptoms?
Cataracts are insidious, and the patient may not experience any symptoms at first. Symptoms usually include the following:
- Blurred vision
- Colors seem dull or faded
- Difficulty seeing in the dark
- Double vision
- Frequent changes in prescription lenses as eyesight worsens
- Glare, as light sources appear too bright
- Haloes around lights
The patient’s symptoms may vary depending on the type of the cataract they have. A patient with a subcapsular cataract may not develop any symptoms until their cataract has become quite large. Patients with nuclear cataracts often develop “second sight,” which is a temporary improvement in their close vision. Unfortunately, as the cataract grows, the effect fades, and the patient’s eyesight continues to deteriorate.
How are cataracts treated?
Patients with cataracts will eventually need surgery. During the procedure, our surgeon removes the defective lens and replaces it with an artificial lens called an intraocular lens or IOL.
Cataract surgery has an excellent success rate; about 90 percent of patients regain vision in the 20/20 to 20/40 range. If you have or suspect you may have cataracts, schedule an appointment with Live Oak Ophthalmology in Wilmington. We will address your needs with superb, customized care.