got diagnosed with glaucoma in only my left eye, questions regarding disease progression and prognosis

i got diagnosed with gluacoma today at 27, i didn’t have my last checkup in about 4 years at which point there was nothing to suggest that i had gluacoma. it’s only in my left eye but my vision is totally fine with no blurryness. But my doctor basically implied that there was significant damage done and my left eye was of a 70 year old man who was diagnosed at 60 and received no treatment for the 10 years. how does this disease progress when do you guys think it started for me within the last 4 years, and what is the prognosis in a case like this? i have been prescribed eye drops and will be seeing a specialist who according to the doctor might overtreat me with a higher dosage. the pressure in my eyes is also normal but the drops are to reduce the pressure in hopes that i maintain my vision

edit: i also have assymetry in my nerves and have a family history