All international students can take the advantage of “general health insurance” coverage in Turkey. If you have the "general health insurance", you can use all state hospitals without a fee and also private hospitals paying a moderate fee. For benefiting from the General Health Insurance System in Turkey, you should firstly go to the International Student Office to get information. Then you should go to the Social Security Institution with neccessery documents to apply it personally. When you complete your application, you will pay your general health insurance fee which is determined on an annual basis within 1 month from the date of Social Security records.
If you don't apply for general health insurance system within the given time period (in 3 months), you cannot benefit from the general health insurance services of the State. But, you can use your international health insurance if you have one or you can get private health insurance in Turkey. Some universities may also offer special insurance policy for their international students.
Please also bear in mind that Turkey is known with its high quality doctors and health facilities, although it has relatively low service prices. Therefore, many people from neighbour countries as well as from developed western world prefer to come to Turkey in order to get healthier and cheaper treatments on dental, eye examinations, surgery, etc.
If we take your residence time into consideration, going to your dentist before your trip; carrying a spare pair of contact lenses and glasses (and take your optical prescription with you); and carrying a first-aid kit will be helpful for you.