Do dental xrays pose risks to eyes (no glasses) if taken high up,(to see root,etc)? and, do all modern machines have auto timer to control exposure?

No risk: Machines are calibrated and checked periodically by the local health department to insure that the dosage being administered is acceptable. Do not worry.

Very safe: When all standard safety precautions are taken, dental X-rays are very safe with minimal radiation and maximum resolution. Today's X-ray equipment is able to eliminate unnecessary radiation. The test is necessary for a proper diagnosis.