If you are receiving Social Security, veteran's benefits or any other form of government benefit check, it may very well be your lifeline. You cannot afford to have it lost or stolen.

The first place your checks become vulnerable is your mailbox. In some cities, organized crime syndicates recruit teen-agers to rip open mailboxes and steal Social Security and other benefit checks.

Sure, you can get a duplicate check issued, but that can take several weeks. Meanwhile, what do you use for money? How do you eat or pay your rent?

Even worse than the mailbox ripoff is getting held up or mugged just after you've cashed your check. Then you don't get any reimbursement. It's a financial tragedy.

Almost every bank, savings and loan, and credit union has a "direct delivery" system for Social Security and veterans checks. This means the check are sent directly to your account at the financial institution you specify.

This way, you are guaranteed to receive the money with no delay, no theft, no fear. If the mails are delayed, you get your money anyway. You can "bank on it."

The financial institution you designate can then put your money in a savings account, a checking account - whatever you wish. The institution might also pay your utility bills, your landlord, mortgage or whatever (many will do this, but not all - shop around). Your major "lifeline" bills are paid, and you get receipts.

The same kind of deal can be negotiated for other "lifeline" checks such as SSI, workers compensation, even alimony. Unfortunately, public assistance or welfare checks cannot be delivered directly to a bank or some other financial institution (except in certain Pennsylvania urban areas).

Another way money is lost is through debt-collection agencies. If you find that your money has been diverted from a bank account into paying off a particular debt, and it's money you need to survive, you need to learn your rights.

No creditor or collection agency can touch money from Social Security, veterans, workers compensation, welfare or any other public-assistance source. You are judgment-proof, no matter what action is threatened.

However, if you mix your government benefit checks (federal, state or local) in with other income or savings in the same account, you might have trouble. Your best bet, according to William T. Vukowich, a professor at Georgetown University Law Center, is to "maintain a savings or checking account into which only your benefit checks are deposited." Vukowich also suggests the checks be in an account that provides free withdrawal anytime without penalty (avoid long-term savings certificates).

The only debts you might be forced to pay (from your benefit checks) are child support and alimony. Even here, according to Vukowich, the issue has not been completely resolved and "the courts will have the last word."

Q. I read about a new kind of contact lens used in England and Europe that can be worn without removal for four months or more. Why aren't these lenses available in this country?

A: "Long-wear" contact lenses are now available in England and Europe, but wearers usually take them out once a week or so for cleaning. Some people have left them in for as long as four months, but this is the exception and not the rule.

They are not available commercially in this country because they have not yet been approved by the Food and Drug Administration, which regulates "medical devices." The lenses must go through extensive testing before they can be approved.

At least three manufacturers are testing the lenses on volunteer patients. If you want to be a guinea pig lens wearer, your optometrist or ophthalmologist might be able to put you in touch with the manufacturers.

The pros and the cons: According to an ophthalmologist at FDA, the new long-wear lenses can be a great convenience, particularly for older patients who have had cataract operations and must use contact lenses.

On the other hand, these lenses might, in the long run, be found to cause damage to the cornea in the eye or might be eventual breeding grounds for infectious bacteria. They will also cost considerably more than regular contact lenses and will be more delicate and easy to break or damage.

Eye specialists suggest that people who want to wear contact lenses for prolonged (daily) use, say, during working hours and for an evening out after work, should remove the lenses for an hour or so after work before going out. Removing contacts at various intervals during the day can make them more comfortable for longer use.