'Seeing' and lookout
There's probably several reasons why glider pilots tend to spot other aircraft quite quickly, including:
- They constantly maintain a good scan cycle
- Maintaining a good lookout out is part of the training
- Gliders fly in quite a, potentially, high risk environment - due to proximity of other gliders and the potential for powered pilots who are staring at instruments instead of looking out (not necessarily a criticism, jus a fact of life)
- Because they're habitually looking out, their visual systems are trained better to do the task
Something that will help is to understand a little more about how your eyes work - and the fact that, without an object to look at, they will naturally focus on a point a few metres away - which is pretty useless for a pilot! A trick to overcome this is to focus on an object on the horizon (or on the ground) and actually look at it properly so that it is in focus. Then move your scan (left or right) and focus on the next object in the distance. This will help to train your eyesight as well as improve your chances of seeing something.