Yes, I was also once told by a teacher to look at the greenery for at least 15 to 20 minutes of a day. But it's my fault that I couldn't follow his suggestion. I still regret it. However now I try to look at greenery as my as I can.
For you, I want to say please, go for an eye check up and do as doctor's prescription. From my experience I will say, the problem of eye-sight must go sought day by day if we ignore to take care of it. Using glass sometimes helps eyesight not to get poorer.
Thanks for stopping by :)