Cataracts Defined: What Are They?
A cataract forms when the lens in your eye becomes cloudy and is the most common cause of vision loss in individuals over 40. Cataracts are also the principal cause of blindness worldwide.
Types of Cataracts
There are different types of cataracts. Different types of cataracts occur in different parts of the lens and are caused by a variety of different factors.
A nuclear cataract forms deep within the central zone (or nucleus) of your lens. This type of cataract is generally associated with ageing.
Cortical cataracts are characterized by white, wedgelike opacities which begin on the periphery of your lens and slowly extend towards the centre like the spokes on a wheel. This type of cataract occurs in the cortex of your lens, which is the part of your lens that surrounds the central nucleus.
Posterior Subcapsular Cataract
Posterior subcapsular cataracts occur at the back of your lens. This type of cataract is most common among individuals who have diabetes or who are taking steroid medications. Both diabetes and steroids can dramatically increase your risk of developing posterior subcapsular cataracts.
Other Cataract Causes
Though the most common types of cataracts are nuclear, cortical, and posterior subcapsular cataracts they are not the only types. Cataracts can form for a variety of other reasons.
Congenital cataracts are inherited and occur in approximately 0.4% of all newborns. Congenital cataracts may be present from birth or may develop shortly afterwards. Luckily, congenital cataracts can be surgically removed. However, since even the safest surgery still carries some risks your doctor may recommend against surgery depending on the severity of your child’s cataracts. Children with very small cataracts, or whose cataracts only affect the peripheral portion of their lenses, may not require surgery.
Secondary cataracts can occur after you have already undergone cataract surgery. During cataract surgery, a significant amount of the front of your lens must be removed so that your surgeon can gain access to your cataract. Once your surgeon has access they can break up the cataract, remove it, and replace the portion of your lens that they removed with an intraocular lens. However, during the procedure, the posterior portion of your lens capsule (the area behind the lens) is left intact, and the new intraocular lens is placed in front of it.
In rare cases, the posterior portion of the lens may become cloudy in the months or years following your surgery. This new cloudiness is called a secondary cataract.
Traumatic cataracts can occur if the lens fibres in your eye become disrupted due to blunt or penetrating ocular trauma. The best way to avoid developing traumatic cataracts is to use protective eyewear when working in dangerous environments or playing sports.
Radiation cataracts occur when you have been exposed to high levels of radiation. Whether or not cataracts form in your lenses depends on how much radiation you have been exposed to. For more information on the relationship between radiation and cataracts please visit the International Atomic Energy Agency’s website.
Cataract Symptoms & Indicators
Cataracts can affect our vision in a variety of ways including:
- Distorting our Vision: Cataracts may cause our vision to become distorted resulting in vision that is cloudy, blurry, or has halos. It may also cause double vision (also called diplopia).
- Making Our Glasses Less Effective: Glasses are designed to help our lenses focus light on our retinas, giving us clear vision. However, cataracts can interfere with this process, rendering our glasses less effective or completely ineffective.
- Straining Our Eyesight: Cataracts may cause additional strain on our eyes. Individuals with cataracts may find that bright lights appear too bright (glare) or have halos around them. They may also find that they have trouble seeing at night or in low light. In some cases, cataracts may cause double vision or multiple vision in one eye.
- Tinting Our Eyesight: As cataracts progress colours may begin to fade or your vision may become tinted more yellow or brown than it used to be. This occurs because of the protein clumps in the cataract, which may affect what colours your eyes are best able to perceive.
- Causing Blindness: If cataracts remain untreated they may cause total vision loss. That is why it is important to see your optometrist regularly, so that vision problems or potential vision problems can be addressed as soon as possible.
Risk Factors That Can Lead to Cataracts
There are a variety of factors that can increase your chances of developing cataracts. These can include:
- Getting older: As we age so do our eyes, which can cause some of the protein in our lenses to clump together. This slowly clouds a small portion of the lens, causing cataracts. This initially small cataract may grow over time, becoming larger and more opaque and making it increasingly more difficult to see.
- Smoking: Smoking causes a wide number of diseases including heart disease and cancer. However, smoking can also cause your risk of developing cataracts to increase. People who smoke are roughly twice as likely to develop cataracts than non-smokers, and that risk continues to increase the more you smoke.
- Diabetes/high blood sugar: Having diabetes or high blood sugar can cause a variety of eye-related problems including an increased risk of developing subcapsular cataracts. Individuals with diabetes require extra care and attention when it comes to their eyes, so it is important that they see their optometrist regularly.
- Family History: Our genes also play a role in our chances of developing cataracts.
- Medications (steroids): Individuals who are on medications that contain steroids have an increased risk of developing subcapsular cataracts.
- Radiation Exposure: Exposure to radiation is hard on our body, and even relatively small doses can have wide-reaching consequences. When our eyes are exposed to radiation it increases our chances of developing radiation cataracts.
- Improper UV Protection: Everyone loves to have fun in the sun, but UV radiation is extremely hard on our eyes. Wearing a pair of sunglasses with UV protection is easy to do, and will help you keep your eyes cataract free.
If you get cataracts there are a variety of treatment options available that can help you maintain your quality of life while living with cataracts. However, the only way to get rid of cataracts is through surgery. Cataracts typically only need to be removed once they begin to cause vision loss that interferes with your everyday activities and impacts your quality of life. Delaying cataract surgery is unlikely to cause long-term damage to your eye or make the surgery more difficult. However, sometimes a cataract should be removed even if it is not impacting your vision. For example, you should have your cataract removed if it is interfering with the examination or treatment of other eye problems such as age-related macular degeneration or diabetic retinopathy.
What You Can Do At Home
The early symptoms of cataracts can be mitigated in a variety of ways including:
- Getting new glasses. A new prescription may help improve your vision in spite of your cataracts.
- Installing brighter lights. If your cataracts are small you may be able to improve your vision simply by installing brighter lights in your home.
- Using anti-glare sunglasses. If you find your vision is particularly affected by bright lights you may be able to use anti-glare sunglasses to help reduce glare and halos.
- Using a magnifying glass. If your cataracts are impacting your ability to read you may be able to work around this problem by using a magnifying glass to read small text.
Cataract Surgery and Recovery
Cataract surgery is a simple and relatively painless procedure and is very successful at restoring vision. Nine out of ten people who undergo cataract surgery regain their vision, and can expect vision between 20/20 and 20/40.
Before the Surgery
A week or two before your surgery your optometrist will want to conduct a variety of tests. These tests may include measuring the size and shape of your eye as well as measuring the curve of your cornea. This information is important and helps your optometry team choose the right type of intraocular lens to suit your vision needs.
You will also likely be asked to not eat or drink anything for about 12 hours before your surgery.
During the Surgery
At the hospital or eye clinic, your pupils will be dilated using specialized eye drops. The area around your eye will also be washed and cleaned in preparation for the surgery.
Your operation will typically last about one hour and will be virtually painless. Though many people choose to stay awake during the surgery you may opt to be put to sleep for the surgery as well. If you opt to stay awake the nerves in and around your eye will be numbed using an anesthetic.
Once the surgery is complete your surgeon may place a patch over your eye and you will be placed under observation for a while so that your medical team can watch for any potential problems such as bleeding. However, most people who undergo cataract surgery can go home the same day. However, you will need someone to drive you home.
After the Surgery
The first few days: Many patients experience mild discomfort or itching after cataract surgery, and you may also experience some fluid discharge from your eye. You may also find that your eye is sensitive to touch or light. If you experience any discomfort during your recovery process you should speak to your optometrist, who will be able to make treatment suggestions. Your discomfort should disappear after a day or two.
The first few weeks: In the weeks following your surgery, you may require eyedrops to help promote healing and reduce the risk of infection. These eye drops will be provided by your optometrist. Your optometrist will also show you how to use these eye drops, and tell you how often you should use them and what effects they may have. You will also need to wear an eye shield or glasses to protect your eye. You should avoid rubbing or pressing your eye.
During your recovery, you should avoid bending from the waist to pick up objects from the floor and avoid lifting heavy objects. However, you may walk, climb stairs, and do light household chores.
Your eye should be completely healed in about eight weeks. During your recovery, your optometrist will want to schedule eye exams to check on your progress.
Possible Post-Operative Problems
It is rare for patients to have any problems after surgery, but they can occur. These problems could include eye infections, bleeding, inflammation, loss of vision, double vision, and high or low intraocular pressure. All of these problems can be treated with prompt medical attention. In rare cases, the tissue around your intraocular lens may become cloudy and blur your vision. This condition is called secondary cataracts and can be treated effectively using a laser.
Consult With Your Doctor
Individuals over the age of 60 should undergo a comprehensive dilated eye exam at least once every two years, and all adults should undergo a full eye exam at least once per year. If you have cataracts and are considering cataract surgery you should consult with your optometrist before making a decision.