1. Literally, to look off or into some distance beyond or in front (of someone, something, or oneself). It's impossible to see ahead in this snow storm. You can't see ahead of these sharp turns on the road, so you'll need to take them very slowly. The rain was pouring down so torrentially that we could barely see in front of our own two feet.
2. To be able to predict or anticipate what will happen in the future. The CEO of the company saw ahead to the future of the industry, and she realized that they needed to drastically change their business model to stay alive. There is of course no way to see ahead in life, so spending your time worrying over every decision you make is futile.
see ahead (of someone or something)
to be able to see into the distance in front of someone or something. The fog was so thick I couldn't see ahead of the car. I can't see ahead, so I will have to stop.