You are comparing apples and oranges. In terms of difficulty, in terms of amt of schooling, it's completely different. Doctors can make more money, really depends on the specialty some will make significanly more money then optometrists. But your life will probably be less stressful as an optometrist. If you are only b/w the two for the money, as a grad from carib school you will probably be relegated to only select few specialties and at certain hospitals. But as a Carib grad you can get ER or GAS, which are both lifestyle oriented. In ER you can make anywhere from $75/hr to $300/hr, depending what group you are in. You can have a 40hr week and 3-4mos vacation to boot. The drawback is that its a chaotic enviroment, you never know what is comin through the door. You are constantly on the move for majority of your shift. When you are there you are basically busting your ass. You see the poor and indigent, since no ER can turn down a person in need, particularly in large innercity/urban centers. And you are constantly looked down upon by colleagues, who look at you as jack of all trades type doctor, who knows many things but not an expert in any one of em. Those are benefits and drawbacks. There is also a high rate of burnout if you really don't enjoy that type of work. As well as an ER physician you are a fat target for lawsuit.
With anesthesia, you can make good money, you tend to work nights and days. Vacation is extensive 1-2mos per year. Pay is good. The drawbacks are boring work, you sit and take vitals for most of the time. Now you do get paid your money's worth when pt is crashing, but generally it's boring. With GAS you are also a target for lawsuit, as well CRNA's are moving in agressively onto your turf and they are a cheaper work force. A hospital can basically hire 1 anesthesiologist to supervise 10 CRNA's, and it's cheaper for em.
But in both of those specialites you can make 200+ per year, more if you want to work harder. All in all it's good cash. But mind you gettin there is 7 years for ER, 8 for GAS. If cash is your biggest motivation ER medicine is fastest and quickest way to get to substantial amt of cash.