What is cataract /. When it is required to be operated ?

My mother aged 68 years and controlled diabetic patient and now she is having problem of cataract with 70% visibility, 30% cloudy.Is surgery required immediately or any other prevention to prolong surgery.......?

is there any chance for other eye to be effected ?

A cataract is a cloud over the lens of your eye, which is usually clear. The lens focuses light onto the retina. A cataract makes everything you look at seem cloudy. The list of treatments mentioned in various sources for Cataracts includes the following list. Always seek professional medical advice about any treatment or change in treatment plans.
Higher-wattage lighting
Eyeglasses
Cataract surgery - there are different types of surgery:
Phacoemulsification (phaco)
Extracapsular surgery
Intraocular lens (IOL)
Laser eye surgery
Control diabetic blood sugars

cataract is a clouding of the lens of the eye. it is not reversible. to my knowledge, surgery is the only treatment. the surgery has become quite fast and easy, as surgery goes. people usually have it as an outpatient and go home that day.

Cataracts are fairly common. Surgery is usually done when vision is lost pretty much in the effected eye. You must be extremely careful after surgery to avoid a detached retina which can cause permanent blindness in that eye..

Here's the lay-down. Your mother is going to die. I'm sorry, but I thought you're better off hearing it from a complete stranger who would forget about you in the next 5 minutes than your doctor who will forget about you in the next 4 minutes 59 seconds. Maybe not this year, maybe not next, maybe not for another 20 years if she mamages her illness. But the point is, she is going to die, and without treatement, she will die blind. With treatment (at the age of 68), risks increase for side effects such as blindness (which will happen anyway) or death (pretty sure about this one too), but it does mean that her quality of life will be dragged up immensely. My 85 year old grandma had cataractic surgery a few years back, and she's still alive and kicking. Well, not so much kicking but slowly rising the leg and back down. There are no requirements to operate. She won't die of it. In fact, the hospital can even chose not to do the surgery if the risks are to high, but she should get it. Recent advancements includes the possibility of a non-surgical option, as well as "fake-breast-like replacements (as in limited focusing abilities as opposed to a set focus)"

Has she seen an Ophthalmologist? If she hasn't, she should. He/she can help her with her cataract.

A cataract is a scaring of the eye's lens mostly due to exposure to sunlight. It can be easily removed in an office surgery. The patient must not bend over or lift anything heavy after the surgery for 24 hours.

The eye will heal quickly. Usually, the doctor will do a separate surgery on one eye and allow it to heal and then the other eye.

Good luck to your mom!