Thank you for your question. If glaucoma remains untreated, the natural progression is a progressive loss of vision. Usually this starts in the periphery and continues to progress until central vision is diminished or lost. During this process, patients often notice a loss of contrast visions (difficulty in telling similar shades of color or grays). Once the vision is lost, it is nearly always permanent. Because the pressure is likely still elevated, patients often still feel pain in or around the eyes, have headaches, or other symptoms. Just because the vision has been lost, this does not stop the other symptoms. It may be beneficial to have the cataract removed if the cataract is causing closure of the natural drainage system in the eye (i.e. narrowing of the angle). However, if the angle remains open, cataract surgery is not likely necessary unless the physician cannot see to the back of the eye to manage other eye problems. If you are concerned, I suggest that you obtain a second opinion from a glaucoma specialist.

You are correct that the eye drops, lasers, and surgeries are often expensive. However, your sister-in-law is 75 and may well live for quite some time. I think maintaining the remaining 30% of the vision that she does have would be beneficial. Complete bilateral blindness often can be expensive as well because the blind patient often needs full-time assistance to help with their activities of daily living. Often, maintaining even a small amount of vision can help these patients maintain some independence and quality of life.