Current estimates reveal there are 253 million people living with some form of visual impairment worldwide, these include common conditions you or someone you know experience every day. Estimates also show that preventative treatment and cures are available for 80% of these widely shared conditions.
So, what are some of the most common visual impairments, and how do they affect the way we see the world? We will explore five common conditions and the visual limitations they present for those affected. We also consulted Damian Lake from the American Academy of Ophthalmologists who offers insight and tips on how to cope with a visual impairment.
A cataract refers to the clouding of the eye's natural lens located behind the iris and the pupil. There are three different types of cataract:
- Subcapsular - found at the back of the lens
- Nuclear - forms in the nucleus of the lens
- Cortical - starts in the periphery of the lens and works inwards
The direct causes of cataracts are still unknown, but the American Academy of Ophthalmology has identified several factors that contribute to an increased risk of impairment - these include family history, eye injury, diabetes, and smoking.
Living with cataracts can be difficult, affecting your view of the world with symptoms that include foggy vision and lights that appear with 'halos' around them. Above we've provided a glimpse of what's it's like to read with cataracts.
Living with cataracts affects the way you see the world around you and it can be difficult to focus on particular things like words or physical objects. Your vision will appear cloudy as if there is a mist in front of your eye.
Sometimes you will also see a 'halo' around a light which can affect the way you see it, giving you a sense that the light is brighter than it should be.
Treatment for cataracts may include corrective reading glasses or contact lenses and brighter reading lights in the short term, but the only long-term solution is a surgical procedure to remove and replace the affected lens.
Consultant Ophthalmologist, Damian Lake, said: "There is no certain way to prevent cataracts but a healthy diet with antioxidants such as vitamin C and E at recommended daily levels show some evidence of reducing your chances of developing cataracts."
A common but rarely discussed side effect of both type 1 and 2 diabetes, diabetic retinopathy occurs when blood sugar levels spike, resulting in damage to the back of the eye and blindness if left untreated.
You can reduce your chances of developing diabetic retinopathy by maintaining healthy blood sugar, blood pressure, and cholesterol levels.
Early symptoms of diabetic retinopathy include worsening vision, sudden vision loss, floaters in your field of vision, and blurry vision, in addition to sporadic pain or redness around the eye.
Above is an example of what you would see if you were trying to read with diabetic retinopathy:
When you're trying to read something, but you have diabetic retinopathy, it can be tricky to make out individual words or letters, especially if the font is too small. Your vision becomes blurry, and there are eye floaters to contend with.
As diabetic retinopathy develops, it becomes more and more difficult to read. The symptoms will gradually worsen over time. There is also the chance of pain and inflammation to the eyes.
Treatment is only recommended when there is a serious risk of vision loss, options include laser treatment, surgical scar removal, and medicated eye injections. If there is no significant risk to vision, the American Academy of Ophthalmology recommends managing diabetes effectively to mitigate symptoms of diabetic retinopathy.
Damian adds: "If you have diabetes the preventative measures you must take include strict control of your blood glucose, no smoking, control your blood pressure."
Sometimes referred to as AMD, age-related macular degeneration affects the middle field of vision and is most commonly found in people in their 50s and 60s. Sufferers of AMD don't always experience blindness, but most have difficulty managing daily activities such as driving or watching TV.
If you have AMD, you will experience a wide range of symptoms, including color dullness, objects that seem smaller than they appear, straight lines that surface as wavy or even hallucinations.
Reading this article would be particularly difficult for someone with AMD because of the need to focus so intently. See for yourself in our representation:
Living with macular degeneration can be really difficult as it affects your ability to focus on everyday tasks such as reading a book. This condition can make objects appear smaller than they are, colours appear less bright and even make straight lines appear wavy.
Macular degeneration can also lead to hallucinations, and although they are uncommon, they can be particularly frightening for the person experiencing them.
There is a wide spectrum of treatment options available depending on the severity of your condition, these include visual aids, regular eye injections, and photodynamic therapy.
"The prevalence increases markedly for those over the age of 75. The main risk factors are age, genetics and cigarette smoking but there is some evidence of an effect on those with heart disease, obesity, high blood pressure, and high cholesterol", says Damian Lake.
Glaucoma is a common eye condition that occurs when the frontal optic nerve becomes damaged due to a build-up of fluid and a subsequent increase in ocular pressure. This condition is most common in people over 70 and may lead to sight loss if left untreated. This visual impairment can cause several symptoms which include:
- Intense eye pain
- Nausea and vomiting
- Red eye
- Tenderness around the eyes
- Rings around lights
- Blurred vision
Glaucoma is a difficult condition to diagnose as a lot of the symptoms are invisible to the naked eye. However, our image above shows how a paragraph of text might look to a person suffering from glaucoma:
Symptoms of glaucoma are mostly invisible and include eye pain and headaches which can make it difficult to explain and diagnose.
As glaucoma develops, blurred vision becomes a symptom which gradually worsens over time and makes it hard to focus. Although it is a common condition, glaucoma can eventually lead to sight loss if left untreated.
Currently, there is no treatment to reverse vision loss caused by glaucoma, but there are preventative measures you can take to avoid further damage. These include medicinal eye drops, laser treatment, and surgery if necessary.
"Acute glaucoma is treated with a laser to create an opening in the iris, and medicine to decrease the pressure in the eye and occasionally an operation to remove the lens." says Damian, "However, in chronic glaucoma, the treatment is usually daily drops to decrease the eye pressure but occasionally either laser to decrease the creation of pressure in the eye, or an operation to increase the outflow is used."
Of the five visual impairments we've discussed, retinal detachment is the least common but remains prevalent in those over 60. Retinal detachment occurs when the thin layer of light-sensitive nerve tissue separates itself from the layers underneath, which causes your vision to become distorted and blurred. There are three types of retinal detachment:
- Rhegmatogenous - this is the most common type and is caused by a hole or tear in the retina
- Tractional - the retina is pulled away by scar tissue within the eye
- Exudative - the rarest form, caused by fluid leaking from the blood vessels underneath the retina
Retinal detachment is a serious condition that requires early detection and treatment to avoid permanent vision damage. Initial symptoms include floaters in the eye and flashes of light that can progress into more serious symptoms such as curtains or shadows spreading across the eye.
Our image above shows what it would be like to read this article with a shadow across the eye which can be a frightening experience when brought on suddenly or unexpectedly.
Retinal detachment is a frightening eye condition for those who experience it and will need to be treated quickly to avoid any lasting damage to the affected eye.
It will usually begin with 'floaters' which can move around and make it difficult to focus. These will then gradually develop into a shadow across the eye and then appear as a curtain moving across the line of sight.
Once you've received a retinal detachment diagnosis, your treatment plan will likely include a prompt surgical procedure to ensure the retina can reattach before your condition causes irreversible damage to the eye.
Damian also adds: "If you develop any flashing lights or new floaters in your field of vision this can be a sign of a retinal tear which may predispose to a retinal detachment. Here, it is safest to get a checkup urgently with a qualified health professional."
The conditions we've covered have varying treatment options depending on the severity of your impairment. It's important to look after your eye health as early detection can be the difference between a clear view of the world and permanent vision loss.
If you think you may have one of these conditions, it's a good idea to speak to your optician about the treatment options available to you. If your treatment options include visual aids, we invite you to look at our wide range of contact lenses.
Mr. Damian Lake is a member of the American Academy of Ophthalmologists, and a Consultant Ophthalmologist and Clinical Director at the world-renowned Queen Victoria Hospital, UK. Visit his website here.