Is There Fillers for the Top of Feet to Hide Veins?

The goal of treatment is to identify whether the visible veins are true varicosities, or abnormal veins, or whether the problem arises from thin skin and subcutaneous tissue. The options for treatment include the following:

Injection sclerotherapy
Microphlebectomy
Fat grafting
Sculptra injection

The choice of treatment is based on the thickness of your tissues and the caliber of the veins.

Certainly fillers are done for the top of hands to hide veins. Doctors have used fat injections, and products such as: hyaluronic acids such as Restylane and Juvederm, and Radiesse (these are not FDA approved uses for these products).
There is a concern that there will be more voluminous and long term swelling in the feet than in the hands and there may be a greater chance of infection.
If you are thinking of having this done, make certain that your doctor has done this many times in the feet otherwise, you can’t know what to expect as the results might be quite different than in the hands.
Furthermore, there might be trouble in wearing shoes for weeks after the filler is injected.

Generally the feet have greater concerns thant the hand due to a higher likelihood of venous and arterial disease. This is why the feet tend to develop ulcers and the hands do not.
If you are otherwise in excellent health, you could consider the fillers used for the hands. I have used both Radiesse as well as fat injections.
However I would recommend that you proceed with caution. Infections and complications are more likely in the lower extremities and more difficult to treat.
Another approach of which I am aware but do not perform is the use of slcerotherapy to make the veins less prominent or noticeable. By making the veins smaller or emimnating them, you may not notice them as much. Smaller veins may be eliminated with laser technology whereas larger veins may require injections or surgery. You should visit an individual with expertise in sclerotherapy who can use any of these methods rather than relying on one technique.
I hope this helps!