Cataracts happens when the lens is clouded hence there is no clear vision anymore. Cataracts develops in the lens. The lens is found behind the iris which is the coloured area of your eyes. The function of the lens is to help focus light that comes in through your eyes on the retina such that there is a production of very clear and sharp images on the retina.
The retina is just like a film in a camera. It is made of sensitive membranes that capture images in the eyes and then sends them to the brain through the optic nerve. Normally, the lens is very sensitive and flexible but as age sets in, the lens becomes less flexible, thicker and less transparent and in some cases may become opaque.
This will then cause the tissues found in the lens to begin to stick together forming clumps which will eventually cloud the areas found within the lens. This could be caused by age and some certain medications that can affect the eyes.
Just as the cataract will then continue to form, the lens found in the eyes becomes affected with thicker clumps therefore forming a larger cloud which ends up affecting a larger area in the lens.
This cloud will then scatter and continually block the rays of light coming into the lens thereby preventing several sharply well-defined and well-formed images from reaching the retina. Hence, as a result of this, the person’s vision will then become blurry.
In most cases, cataracts usually develop in both eyes but not always at the same time but eventually, it gets to affect the both eyes. And sometimes, the cataract doesn’t affect both eyes equally. It usually affects one eye more than the other.
The cataracts found in one eye is larger and greater in one eye than in the other causing a different degree of light rays to pass through. This will therefore lead to a very large difference in the type of vision seen in both eyes.
Types
There are different types of cataracts and they include;
Nuclear cataracts
It is also known as nuclear sclerosis of the eyes. This type of cataract usually affects the centre of the lens. Most times a nuclear cataract usually shows up as nearsightedness that is more than usual. Sometimes, it can even exhibit as a massive temporary improvement in one’s reading and likewise seeing vision.
However, as time passes, the lens gradually develops a yellowish colour which will later become dense leading to the further clouding of one’s vision. As the cataract advances gradually, the lens may begin to turn brown and as such will begin to advance.
When this occurs, the patient will experience intense difficulty in distinguishing between different shades of colours. When it gets to this advanced stage, this type of cataract is then known as the brunescent cataract
Cortical cataracts
This kind of cataract affects the edges and sides of the lens. This occurs when the cortex of the lens becomes opaque. A cortical cataract usually proceeds with a whitish streak on the outer layer of the lens.
As this cataracts advances, this streak will proceed and stretch towards the centre and hence interfere with the rays of light passing through the centre of the lens causing the lens to become opaque.
Posterior subcapsular cataracts
This type of cataract affects the back of the lens. Most times, the posterior subcapsular cataract starts as a small opaque area usually at the posterior end of the lens mostly in the path of light rays coming into the eye.
A posterior subcapsular cataract often interferes with the path of a person’s reading vision. It also causes a reduction of one’s vision in bright light and causes a halo-like structure around lights seen mostly in the night. This type of cataract usually tends to progress more rapidly than others.
Congenital cataracts
This kind of cataracts affects young children and new born. Some new born develop it even from birth while the others develop it from their childhood. While some of these cataracts are caused by trauma, some are due to genetic factors while the remaining types of these cataracts are caused by infection.
This type of cataract too can also be due to some diseased conditions such as myotonic dystrophy, rubella otherwise known as neurofibromatosis type II, and also galactosemia etc.
This congenital defect doesn’t usually affect the child’s vision initially but if after detected, it isn’t treated, then the child will start experiencing blurry vision. There are different causes of cataracts and they include:
Causes of cataracts
Age
Age is a major factor that causes cataract. When an aged person who also has an underlying diseased condition such as diabetes mellitus, it can cause severe weakening of the tissues of the lens and hereby accelerating the degeneration of the lens.
Environmental factors
Environmental factors such as toxins, excessive exposure to ultraviolet rays, excessive exposure to radiation will cause alteration in the genes of the body and also the genes found in the eye too aren’t left out.
It will cause mutations in the genes of the eyes and severe alterations in the chemical processes that occur in the eyes. This will therefore cause so many complications in the eyes including cataracts.
Genetics
Cataracts can be caused as a secondary condition from some underlying diseases caused by the inheritance of some gene related disorders.
Medications
The side effects of the long-term use of some medications like steriodal based drugs can cause the formation of cataracts.
Trauma
Severe trauma to the eyes can cause damage to the lens and can also cause cataracts.
The following are risk factors for cataracts and they include:
- Age
- Diabetes
- Obesity
- Increased blood pressure
- An inflammation of a previous trauma to the eyes
- Increased or prolonged use of some medications
- Alcohol
Cataracts can’t be treated except by surgery. But it can be managed. When they begin to appear initially, they can be managed using glasses with strong bifocations as that will help improve the condition.
There are certain measures one can take to prevent cataracts and they include:
- Always undergo constant eye checkup: Constant eye checkup can help to detect and confirm eye defects even in their earliest stages.
- Manage every underlying ailment appropriately and treat those that can be treated well
- Stop smoking and also reduce alcoholic intake.
- Always ensure to use sunglasses when necessary.
- Also avoid the exposure to UV rays excessively. If it not necessary, avoid being exposed to it to avoid gene mutations.
