Can you please tell me about the advantages of hard contact lenses?

These: They are the cheapest contact lenses and the vision is the best of all forms of vision correction. The initial cost is high, but a pair will often last 3 years, making the total cost less than soft lenses.

Vision and Care: Rigid contacts can provide better vision as they replace the eye's surface with a perfectly curved one. Soft lenses assume the shape of the eye and don't correct for irregularity. Also, hard lens are more durable and easier to care for. Disadvantages are they fall out easier, are harder to fit, and usually take some time initially to become comfortable. Long term complications can be less vs. Soft.