Before discussing about the symptoms of cataract one should know what are cataract, its causes, and pathogenesis. So what is cataract? Cataract refers to opacification of lens fibers. Depending upon the time of opacification that is whether it occurs during the gestation or after the birth it can be classified into developmental or acquired cataract.
What is the Cause of Cataract?
The cause of developmental cataract is either maternal or fetal cause. The maternal cause include exposure to radiation during pregnancy, intake of any such drugs which induced cataract, nutritional factors, infection and so on. The fetal factors comprises of malnutrition or inappropriate oxygen during labor, which usually occurs in prolonged labor.
The pathogenesis is related to accumulation of fluid and coagulation of proteins. Thus usually occurs when a person is exposed to smoke for a prolonged period of time as it contains certain toxin substance which inhibits the Na/K pump and initiate coagulation of proteins which gets accumulated in the lens fibers.
Now the question arises when patient comes to a doctor, what is the chief complain for which he enters the ward?
The most common complaint with which patient reports is glare which means that due to accumulation of water droplets in the lens fibers patient find it difficult to tolerate bright light.
Colored halos are seen because of breaking of rays of light by the water droplets imparting a prismatic effect.
And most important point is that cataract are painless until and unless associated with other abnormalities. There may be slight headache due to diplopia but there is no complain of pain in general.
Doubling or trebling of vision due to varied refraction is another important concern to keep in mind. Irregular refraction as there is varied refractive index and the main cause for all this is degeneration of lens fibers. When it is congenital it presents usually early and in cases of acquired cataract usually there is diminished vision associated with cataract.
Are Cataracts Painful?
No, cataracts are not painful. Vision deterioration is classically painless and while making differential diagnosis of vision loss one should consider this fact so as to reach the correct diagnosis. And another important characteristic is its progressive nature. One has to take medication to prevent progression of the disease. Depending upon the site of opacification cataract can be divided into various categories-
Day blindness seen in person who has got central opacification that is posterior subcapsular cataract. Such person has a better vision in evening hours when pupil is dilated.
When there is peripheral opacification person usually have a better vision in day time when pupil is contracted. Thus this type of blindness is known as night blindness.
In patient with nuclear sclerosis distant vision is usually impaired. This occurs due to progressive index myopia.
There is so much accumulation that patient complains of blurred vision and deterioration of images.
So while diagnosing a case of cataract all these symptoms should be kept in mind along with painless vision loss. This is a classical symptom which helps us to differentiate from other disease of eyes.
Since cataract is painless there is no need of prescribing analgesics in such person. The only treatment of cataract is surgery as it is progressive in nature and can get relieved with surgery. Symptomatic treatment can provide support to an extent but last resort is surgery.
Depending upon the choice of the patient appropriate surgery should be done. If in case person is reluctant to go for surgery one is explained about vision loss. Cataract initially was considered a dreadful disease, presently can be treated with ease as there are lot many facilities available. Excluding primary health center each and every health facilities these days have got basic cataract surgery facilities.