About Dry Eyes

The normal tears are formed of three layers: an oily (lipid) layer; a watery (aqueous) layer; a sticky (mucous) layer. All three work in harmony to protect, nourish and moisturise the eyes. Also, they refract or concentrate the light to help us see better. When we blink, which we do roughly every 4-6 seconds, our tears are refreshed.

Dry eyes occur when there are not enough good quality tears to lubricate the eyes. The medical term for it is keratoconjunctivitis sicca and can be classified into two main types:

Aqueous deficient
When the eye does not produce enough of the watery part of the tears so the tears do not moisturise the eye enough
Evaporative
When the top oily layer is not working correctly and tears disappear too quickly (often associated with blepharitis and meibomian gland dysfunction).

The symptoms of dry eyes include:

Sore, uncomfortable eyes
Watery eyes: this might seem counter-intuitive but is a sign of poor quality tears and is often an indicator of early, mild dry eye
A dislike of bright lights
A feeling that there is something in the eye
Short term blurred vision

Causes of dry eyes:

Getting older
Hormonal changes in women such as the menopause
Medication such as beta blockers, the contraceptive pill, anti-histamines and anti-depressants
Medical conditions such as Sjogren's Syndrome, rheumatoid arthritis, diabetes, thyroid disease, lupus
Blepharitis and or meibomian gland dysfunction (MGD)
Laser eye surgery
Inefficient blinking or eyelid problems
Environmental factors:
- air conditioning
- central heating
- wearing contact lenses
- flying
- smoking

As a general rule, if eyes are drier in the morning after the eyes have been closed overnight then blepharitis/meibomian gland dysfunction could be the root cause. If the eyes become dry throughout the day, then a lack of or increased evaporation of tears from the surface of the eyes is the cause.

What can I do to help?

Dry eye drops and gels to help relieve the symptoms of soreness and irritation in the eyes. There are different types of lubricants and preparations that can be more or less effective for different reasons. You can read more in our buying guide 'How to choose Eye Drops'.
Eye gels or ointments are thicker preparations that tend to have a longer lasting effect. They are better for use at night when reapplication is less practical. You can read more in our buying guide 'How to choose Eye Drops'.
Lid cleansers such as impregnated wipes, gels, foams or solutions and mild lid massages (to clean the lid crusts and squeeze out any solid secretions that are clogged in the glands). You can read more in our buying guide 'How to select the best Lid Care product'.
Omega 3 supplements to improve the quality of meibum. You can read more in our buying guide 'Supplements for Dry Eyes'.
Heat treatments such as eye masks and goggles can improve blepharitis by gently warming the oily liquid in the glands. This helps to release it and improve the quality of the tears. Many were developed by ophthalmologists and can be re-used hundreds of times. You can read more in our buying guide 'How to choose a Heat Mask'.