Damage from sun diabetes, hypertension,cancers,nutritional deficiencies among many other possibilities

Yes. Because subjective responses are crossed checked with objective findings and instrumentation. The purpose is to find the most comfortable and accurate focusing for youe eyes> 

A comprehensive eye exam considers multiple tests and investigations for the best vision and eye health outcome 

Bring all your glasses, sunglasses, contact lens products ,medication lists, family and any relevant personal eye and health history, to your eye examination.

The condition of your eyes can change over time. Some eye conditions develop so gradually (and why family history is important) they may not be recognised until regular eye exams are undertaken

The American Academy of Ophthalmology recommends having a comprehensive eye exam every five to 10 years if you’re under 40 years old; every two to four years if you’re 40 to 54 years old; every one to three years if you’re 55 to 64 years old; and every one to two years if you’re older than 65. For example if you’re at risk of glaucoma  you would need more frequent reviews.

The amount of the medicare rebate depends on how long it has been since your last eye examination but is typically around $70. Some advanced additional tests that are not claimable on Medicare may be discussed if required. Private health fund claims can be processed using HICAPS
No health fund Gap spectacles and means tested free Government specatcles are also available

No health fund Gap spectacles and means tested free Government specatcles are also available. The price of glasses varies widely with frame prices and lens prices. Despite some marketing claims they are not all the same and have to be a tailored for a specific  prescription. 

Drops may be used to dilate your pupils to allow for more complete assessment,to allow eye pressure testing,tear film diagnosis or to treat and investigate inflammation  and infection.