I think you don't need to worry about this because maggot or larvae seldom get into our eyes or orbit. It is rare case. Just pay attention to eye hygiene and take ascaricide according to doctor's suggestions.
There will be no symptoms if it is just an early infection. So you can't recognize it at this moment. But if you suffer from blurred vision, eye floaters or even pain in your eyes, you may need to have your eyes checked by an eye doctor immediately. Sometimes, these symptoms can be a warning sign of some eye problems or vision problems, but sometimes it can suggest that there is maggot or larvae in my eyes.
The best way is to see an ophthalmologist immediately if you are suffering from blurred vision or pain in your eyes. You may need to tell him or her your symptoms. The ophthalmologist will perform a complete examination including dilating your pupils, checking for any foreign objects or any sign of inflammation. But sometimes, our eye condition could be related to your joint aches, rash or something else, we seldom have maggot or larvae in our eyes, so we don't need to worry about this.
Well, you can see maggot or larvae with unaided eyes. They will move because they are alive. And they are also visible. Besides, there will be continuous eye pain caused by these foreign bodies. I think you must see an ophthalmologist immediately if you suffer from this.