What is a cataract in the eye? Considering that cataract surgery is the most commonly performed eye surgery in the world, it’s most likely that you’ve heard the word “cataract” at least once. However, what a cataract exactly is might still be a mystery to you. Here we discuss what is a cataract in the eye, and the basics of its treatment – cataract surgery.
What is a Cataract?
In the eye is an anatomical structure called the crystalline lens. At birth, a healthy lens is clear and transparent. The function of the lens is to adjust its shape to change the way light focuses around the retina. This process is called accommodation and allows us to keep objects in focus as they come nearer. Because the lens is transparent, light is able to pass through, which is what we need to clear sight.
As time passes, or due to other cataract-causing factors, the crystalline lens may lose its transparency. This opacity or clouding of the lens is what we call a cataract, and can reduce the amount of light able to enter the eye. This results in the typical symptoms of a cataract, including:
- Cloudy, filmy, blurry, or hazy vision. As the haziness of the lens no longer allows light to get through easily, it can deteriorate the quality of your sight.
- Increased discomfort around bright lights. This is also known as photophobia or glare sensitivity. The opacities of a cataract can scatter light entering the eye, resulting in uncomfortable or even debilitating glare. The effects of this may be more apparent at night, such as when driving.
- Increased difficulty in low contrast visibility conditions. Contrast vision is the ability to discern details against a similarly shaded background, for example, black text on a grey page. Where this may have been easy to do before you developed a cataract, you may now need improved lighting to increase the contrast.
- Alterations to colour vision. One particular type of age-related cataract is known as nuclear sclerosis. This appears as a yellowish-brown haze in the centre (nucleus) of the lens. The shifting colour of your lens can affect your colour perception.
- Rapidly changing prescription. Where your spectacle script may have been quite stable for years, you may now find you need to update your lenses every year or even more often in order to keep your sight sharp. A cataract can cause your prescription to shift in any direction, including more long-sighted or more short-sighted.
The most common cause of cataracts is simply increasing age. The theory behind this is that older bodies are less able to combat the effects of accumulated oxidative stress on their tissues. As toxic compounds build up in and around the eye, this can cause the fibres of the crystalline lens to lose the properties that keep them transparent.
There are also other factors that can cause cataracts, including injury or inflammation of the eye, certain systemic diseases, and certain medications. Some cataracts may be congenital, meaning they are first detected within the first year of life. These may be genetic or a result of the mother contracting an illness during pregnancy.
The diagnosis of a cataract doesn’t immediately mean you need eye surgery. Instead, your eye care professional will monitor you until the cataract is having enough of an impact on your sight and lifestyle to warrant cataract surgery.
How Does Cataract Surgery Work?
Cataract surgery is one of the most common surgical procedures and the number one most frequently performed eye surgery. Although the idea of any eye surgery can be daunting, rest assured that cataract surgery is considered to be a safe and effective procedure. It is also the only way of definitively treating cataracts.
As with the majority of eye surgery operations, cataract surgery is a day procedure. Uncomplicated cataract surgery cases can take as little as 20 minutes per eye. Firstly, the pupil of your eye must be dilated, usually with pharmaceutical eye drops. It will then be numbed with a local or topical anaesthetic to make you more comfortable. On the operating bed, your surgeon then creates an incision in the cornea, the front surface of the eye. This allows other instruments to get to the cataract behind the pupil. Once the membrane bag holding the lens and the cataract is opened, the cataract can then be broken into smaller pieces. These fragments are then removed from the eye, providing the space for an artificial lens implant to be inserted into the membrane bag.
Depending on the technique your surgeon is using for cataract surgery, he or she may use handheld tools to perform most of the steps. Alternatively, in femtosecond laser-assisted cataract surgery, a laser instrument can be used to replace all the manual steps. Although the visual outcomes of both techniques are not significantly different, some surgeons will swear by one while others will prefer the other. The use of the femtosecond laser can significantly increase surgery costs, so it is worthwhile doing your research and discussing your options with your surgeon before proceeding.
I Think I Have a Cataract!
If you suspect you are developing a cataract, visit your eye care professional for an examination. This can either be your optometrist or ophthalmologist. Diagnosing a cataract is quite straightforward, and your eye care professional will be able to guide you on the timing for cataract surgery. If you have any further questions about what is a cataract in the eye, they will be best positioned to explain this to you, as well as how your specific cataracts are expected to impact your sight.
Call us today on (03) 9070 3580.
Note: Any surgical or invasive procedure carries risks. Before proceeding, you should seek a second opinion from an appropriately qualified health practitioner.