When you can distinguish surface texture or individual grass blades, it's time to flare. I sometimes have people climb up a TV antenna tower 8-10' to get a sight picture of the grass below that matches when they should be beginning to flare.
That's the time to begin looking at the end of the runway while holding landing attitude and controlling drift. You have to use peripheral vision for the last few feet / inches of descent.
Sometimes in the glider I can hear the grass brushing the tailwheel and just squeeze on a bit more spoiler to bring the main down
Some of us have an ocular defect that leads to late or early flares. The optometrist will suggest prisms and trust me, they make a big difference. Your medical examiner had you look at a slide with red dots against upside down l's. If the line does not go through the middle, see an optometrist about prisms.