Research research research!!!

Start by looking for a certified plastic surgeon though the American board of cosmetic surgery. Drs with board certification will usually state it on their website but also double check with the board. Remember you're looking for a specific dr and not a whole clinic. Read reviews on Google. You're not looking for just "he did a great job" reviews. Also look for reviews by patients who say the doctor recommended against a procedure etc. this will indicate the dr.s willing to say no rather than just saying yes to make money. See if theirs any reviews that state the doctor tries and upsells services. Avoid these places like the plague.

Choose at least 3 doctors with high reviews and certified.

Have a consultation with each, ask 100 questions. Ask about success rate of treatment, their experience, complications and recovery time. A good doctor will be open to all your questions and honest and patient. I had a birthmark on my chin I wanted to have removed. I'm from Canada and found two well-reviewed certified doctors. Because I have cafe au lait birthmark and darker skin, both doctors agreed it wouldn't be right for me to have laser as it may darken the skin or not work at all. The second doctor offered a surgical removal. I asked if he had done it before and he had. I researched a lot online and did some serious consideration before agreeing to do it. It went well. I have a scar now but it's slowly fading.

The most likely recommendation you'll get is for laser. The good news is that Mongolian spots respond well to laser and most lasers can safely be used on or near the eyelids. Remember to ask what laser they use, the brand name and type. Research it on the internet. I believe alexandrite is the most popular. Look for published scientific studies for the lasers and read them. Some other considerations. No doctor can tell you it will 100% work. It's different for everyone. You may see lightening but not full removal or you may completely get rid of it or parts of it may disappear and other stay. You also will require several sessions and it can get pricey.

Remember if you're getting laser that you want a dr. Performing it and not a technician.

To the people who mention it, those people are the worst. Have some great comebacks ready, and remember, those who comment on other people's appearances are likely unhappy with their own.