How can i tell if theres maggot or larvae in my eye?

Highly uncommon: Such things are visible to the unaided eye. If you are experiencing changes in vision or eye pain go see an ophthalmologist immediately.

Need complete dilate: You would need to see an ophthalmologist for a complete examination including dilating the pupil. The ophthalmologist needs to check for any sign of inflammation or foreign body. In addition, you need to discuss any symptoms you might be having. Your eye condition could be related to your joint aches and rash.

Go to your doctor: Early infection can have no symptoms. Most often patients complain of blurred vision, pain or floaters. Go to your doctor to check it out.

Very unlikely: Maggots getting into the eye or orbit is exceedingly rare. Don't worry about this.