The area around his eyes doesn't look good to me.
Is his head wet ?
Is the bird starting or finishing a molt
What makes you think he is sick?
Is he eating, drinking and pooping normally? Is he acting differently than normal?
Any time you are concerned your budgie is ill, the best thing to do is have it seen by an Avian Veterinarian.
Avian Vets have special training to determine the cause of symptoms resulting from illness or trauma.
This is important as "regular" vets will often overlook symptoms that are quickly obvious to an Avian Vet.
When you rely on anyone who has not had training in Avian diagnosis and care, you may be delaying effective treatment.
This can prolong suffering that may be avoidable.
The bird will often require a more intense, prolonged treatment with a poorer chance of full recovery than it would have if you seek prompt professional diagnosis and treatment at the first sign of illness. If there are no Avian Vets near you, please find an Exotic Pet Veterinarian with experience in dealing with small birds.
Having your budgie examined by an Avian Vet allows you to develop a good relationship with the vet in case your bird needs care for an injury or illness in the future.
Additionally, it is always helpful for the vet to have a baseline for your bird to refer to should it need future treatment. Avian Association of Veterinarians
The purpose of this forum is to promote the BEST PRACTICES in the care of budgies for their optimal Health and Well-Being
Your budgie is very cute, but indeed does not look quite right, as FaeryBee mentioned above. Additionally, are you aware that he has a very severe underbite? Even if he is just having a severe moult and has no other symptoms, it's very important to have all of this checked out at an avian vet to ensure he has the best quality of life possible, assuming his underbite is permanent.
You've come to a great place to learn even more about the best of budgie care practices!
Be sure to read through the links provided above by FaeryBee, which include the forums' many budgie articles and "stickies", to stay updated on everything. If you have any questions after doing so, please be sure to ask as we'd love to help.