Thanks for the query,
It might not be related to injury.
Greying of eye lashes is seen in many people,
it is very difficult to ascertain one particular cause.Nutritional deficiency
is thought to be the most important factor in most of the cases.
It can be treated by using bimatoprost eye drop
Also take a multi vitamin tablet daily.
This will give you some relief.
Please meet a dermatologist
for exact diagnosis.
Let me know if you have any other doubt.
you can ask a direct question to me on this forum, following the below link.
Wishing you a good health.