How is it possible that Jon Trenge feels lucky that he'll miss the upcoming EIWA and NCAA tournaments?  In a late Sunday afternoon phone interview, he confirmed Internet stories Saturday morning that he'll miss the next four weeks of physical activity due to eye surgery for a torn retina Friday night at St. Luke's Hospital.     The surgery came within six hours after Jon got trainer Jack Foley's attention by describing his sudden decline in peripheral vision in one eye. The new development was shared during his routine aquatics exercise Friday afternoon with roommate and teammate, Rob Rohn. There was no contact workout Friday for Trenge and he chatted amiably with this reporter prior to this first appointment, without any mention of any concern.    At that time, having little idea of the severity of his condition, Jon visited the University Health Center, then was routed to two opthamologists in Bethlehem for quick and consecutive opinions, where Dr. Amit Gupta made the final diagnosis. Dr. Gupta found two old tears of the retina that had healed and one new one, with no certainty as to when any of them had occurred. While not necessarily from wrestling, had he continued to compete without surgery, it's possible that another torn retina could have cost him his eyesight in at least one eye.  Hence the immediacy of the Friday night operation.    In the interview, Jon said he was handling countless phone calls and deeply appreciated everyone's concern expressed about his health & vision, more so than the disappointment about missing the tournaments. He added his sincerest gratitude to Foley, for his usual concern and follow-up as trainer on behalf of his athletes.     The diagnosis came a little over 10 years after Lehigh senior and defending NCAA champion Matt Ruppel abrupted ended his 4th year of competition with a diagnosis of spondylolysis--a spinal disorder in which the arch of the fifth lumbar vertebrae is found to be weaker than normal and more likely to be deformed or damage under stress. Such incidents help place a proper balance between the value of sports and the truly important things in  life.     The show will go on, with Jon in the role of tournament cheerleader, much like the sidelined Ryan Bernholz performed last March.