A cataract is a clouding of the lens of your eye, which causes a decrease in your vision. Most cataracts develop gradually and won't disturb your eyesight in the early stages. You may not even be aware you have cataracts until they’re more advanced. Over time, cataracts can lead to visual impairment and eventually blindness — both can be reversed with surgery. It’s important to see your optometrist so they can monitor your cataracts and let you know when it’s the right time for treatment.
What are the signs and symptoms of cataracts?
1. Blurry vision
The first and most common symptom is blurry vision. Your eyesight may be cloudy, filmy or foggy. As cataracts worsen, less light can reach your retina (the back part of your eye, which detects light).
When cataracts are in the early stage, you may have blurred spots in your field of vision. The spots will start off as small patches and grow in size over time. As your cataracts worsen, these blurry patches can make daily activities more difficult.
2. Light and glare sensitivity
You may experience glare and light sensitivity as an early symptom of cataracts, as well as halos around light sources. Clear lenses allow light to easily pass through into your eye and become focused on your retina. Cloudy lenses, however, scatter the light, which is what causes glare, halos around lights and light sensitivity — even when your surroundings are not especially bright. This effect can happen indoors (eg seeing halos around ceiling lights) or outdoors (eg more extreme glare from streetlights).
3. Brown or yellowish eyes
Cataracts cause discolouration of the lenses in your eyes. At first, they become tinged yellow and later, in more severe cases, brown. This can affect the way you see colours around you and make it more difficult to tell the difference between colours, especially black, brown, blue, purple and green.
4. Difficulty seeing at night
In the early stages of cataracts, you may first notice changes in your night time vision. Cataracts cause your vision to dim or darken, which you may not notice during the day when there is enough natural light to compensate for your dimming vision. However, this may become apparent at night.
You may find that you need more light when performing tasks at night, dusk or dawn. When you’re at home, you may need to increase the brightness of your digital devices. However, as your cataracts progress, brightening your screens won't help.
5. Faded colours and hazy objects
As your cataracts grow and your lenses become more cloudy, colours may appear faded and dull. Your vision will also become less sharp.
6. Difficulty reading
The lens in your eye is made of proteins and water. When these proteins are aligned, your lens is clear. When you have cataracts, these proteins clump together and make the lens cloudy, which makes reading difficult, especially if the text is small eg on medicine or food labels, in books or newspapers.
7. Double vision or diplopia
Double vision (diplopia) occurs when you see two images of an object at the same time. These images can be on top of each other or side by side. Cataracts can cause diplopia only when you close one eye — this is different from diplopia that occurs when both of your eyes are open, which is caused by an eye condition called strabismus.
8. Changing contact lenses or glasses frequently
As your cataracts get worse, you'll find that you need a stronger prescription in your contacts or glasses. This is a temporary fix and you will eventually need treatment for your cataracts.
As your cataracts develop, you may notice a temporary improvement in your near vision — this is called second sight. It occurs when cataracts begin in the centre of your lenses, causing them to temporarily swell. This swelling improves their ability to focus light from near distances. However, this effect does not last and you will eventually see your near vision deteriorate again.
9. Filmy vision
The damage cataracts cause to your lenses can result in a permanent glaze. You may feel like there is a transparent layer of cloth covering your eyes. This will not go away and may gradually worsen over time. This can affect your depth perception and cause eye strain and headaches.
If you notice any of these signs of cataracts, it's important to see your optometrist or doctor so you can get treatment to improve your vision.
